ALBERT

Description: A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $$5.5

Description: The strong coupling constant $$alpha _mathrm{s}$$ α s is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of $$alpha _mathrm{s} (m_mathrm{Z})$$ α s ( m Z ) at the Z-boson mass $$m_Z$$ m Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be $$alpha _mathrm{s} (m_mathrm{Z}) =0.1157,(20)_mathrm{exp},(29)_mathrm{th}$$ α s ( m Z ) = 0.1157 ( 20 ) exp ( 29 ) th . Complementary, $$alpha _mathrm{s} (m_mathrm{Z})$$ α s ( m Z ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value $$alpha _mathrm{s} (m_mathrm{Z}) =0.1142,(28)_mathrm{tot}$$ α s ( m Z ) = 0.1142 ( 28 ) tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

Description: The stick–slip model of a Girling brake is composed of nonlinear and coupled differential equations that reproduce the friction occurring in this mechanical system. The brake is equivalent to a body sliding on a belt. The problem is very interesting since the possible solutions, which are very sensitive to the parameters of the system, show a chaotic behaviour. In this contribution, the model, which is designed following network method rules, is explained in detail and runs on standard electrical circuit simulation software to provide the displacement and the velocity of the sliding body and the phase planes. In comparison with other models, the considered system does not include dampers to get a more unstable behaviour. Furthermore, a suitable selection of parameters is implemented to reduce the computational time.

Description: A Higgs field of particle physics can play the role of the inflaton in the early universe if it is non-minimally coupled to gravity. The Higgs inflation scenario predicts a small tensor to scalar ratio: \(r\simeq 0.003\) . Although this value is consistent with the upper bound \(r〈0.12\) given by the BICEP2/ Keck Array and Planck data, it is not at their maximum likelihood point: \(r\simeq 0.05\) . Inflationary observables depend not only on the inflationary models, but they also depend on the initial conditions of inflation. Changing the initial state of inflation can improve the value of r . In this work, we study the Higgs inflation model under general initial conditions and show that there is a subset of these general initial conditions which leads to enhancement of r . Then we show that this region of parameter space is consistent with a non-Gaussianity bound.

Description: When Morris and Thorne first proposed that traversable wormholes may be actual physical objects, they concentrated on the geometry by specifying the shape and redshift functions. This mathematical approach necessarily raises questions regarding the determination of the required stress-energy tensor. This paper discusses a natural way to obtain a complete wormhole solution by assuming that the wormhole (1) is supported by generalized Chaplygin gas and (2) admits conformal Killing vectors.

Description: In this article, we study the charmed baryon states \(\Lambda _c(2625)\) and \(\Xi _c(2815)\) with the spin-parity \({3\over 2}^-\) by subtracting the contributions from the corresponding charmed baryon states with the spin-parity \({3\over 2}^+\) using the QCD sum rules, and suggest a formula \( \mu =\sqrt{M_{\Lambda _c/\Xi _c}^2-{\mathbb {M}}_c^2}\) with the effective mass \({\mathbb {M}}_c=1.8\,\mathrm {GeV}\) to determine the energy scales of the QCD spectral densities, and make reasonable predictions for the masses and pole residues. The numerical results indicate that the \(\Lambda _c(2625)\) and \(\Xi _c(2815)\) have at least two remarkable under-structures.

Description: We study the radiative leptonic \(B_c\rightarrow \gamma \ell {\bar{\nu }}\) decays in nonrelativistic QCD effective field theory, and we explore the contribution from a fast-moving photon. As a result, interactions between the photon and the heavy quarks can be integrated out, resulting in the factorization formula for the decay amplitude. We calculate not only the relevant short-distance coefficients at leading order and next-to-leading order in \(\alpha _s\) , but also the nonrelativistic corrections at the order \(|\mathrm {v}|^2\) in our analysis. We find that the QCD corrections can significantly decrease the branching ratio, and this is of great importance in extracting the long-distance operator matrix elements of \(B_c\) . For phenomenological application, we present our results for the photon energy, lepton energy and lepton-neutrino invariant mass distribution.

Description: We point out a weak side of the commonly used determination of scalar cosmological perturbations lying in the fact that their average values can be nonzero for some matter distributions. It is shown that introduction of the finite-range gravitational potential instead of the infinite-range one resolves this problem. The concrete illustrative density profile is investigated in detail in this connection.

Description: A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born–Infeld–Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via the introduction of three nonnegative functions depending only in the Higgs field, namely, \(G(|\phi |)\) , \(w(|\phi |) \) , and \(V(|\phi |)\) . A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampère law. Such a constraint allows one to minimize the system’s energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of the role of topological vortex solutions in Born–Infeld–Higgs electrodynamics. Finally, we analyze a set of models entailing the recovery of a generalized version of Maxwell–Higgs electrodynamics in a certain limit of the theory.

Description: I put forward a qualitatively new dynamical mechanism for solving the electroweak hierarchy problem that does not require new physics at the electroweak scale. I argue that the infrared fluctuations of the gravitational field may provide a partial screening of the Higgs mass, similar to the infrared screening of the electric charge in quantum electrodynamics.

Description: It is thought that the spacetime geometry around black hole candidates is described by the Kerr solution, but an observational confirmation is still missing. Today, the continuum-fitting method and the analysis of the iron K \(\alpha \) line cannot unambiguously test the Kerr paradigm because of the degeneracy among the parameters of the system, in the sense that it is impossible with current X-ray data to distinguish a Kerr black hole from a non-Kerr object with different values of the model parameters. In this paper, we study the possibility of testing the Kerr nature of black hole candidates with X-ray spectropolarimetric measurements. Within our simplified model that does not include the effect of returning radiation, we find that it is impossible to test the Kerr metric and the problem is still the strong correlation between the spin and possible deviations from the Kerr geometry. Moreover, the correlation is very similar to that of the other two techniques, which makes the combination of different measurements not very helpful. Nevertheless, our results cannot be taken as conclusive and, in order to arrive at a final answer, the effect of returning radiation should be properly taken into account.

Description: We investigate unitarity within the complex-mass scheme, a convenient universal scheme for perturbative calculations involving unstable particles in quantum field theory which guarantees exact gauge invariance. Since this scheme requires one to introduce complex masses and complex couplings, the Cutkosky cutting rules, which express perturbative unitarity in theories of stable particles, are no longer valid. We derive corresponding rules for scalar theories with unstable particles based on Veltman’s largest-time equation and prove unitarity in this framework.

Description: We compute the decays \({B\rightarrow D^*_0}\) and \({B\rightarrow D^*_2}\) with finite masses for the b and c quarks. We first discuss the spectral properties of both the B meson as a function of its momentum and the \(D^*_0\) and \(D^*_2\) at rest. We compute the theoretical formulae leading to the decay amplitudes from the three-point and two-point correlators. We then compute the amplitudes at zero recoil of \({B\rightarrow D^*_0}\) , which turns out not to be vanishing contrary to what happens in the heavy quark limit. This opens the possibility to get better agreement with experiment. To improve the continuum limit we have added a set of data with smaller lattice spacing. The \({B\rightarrow D^*_2}\) vanishes at zero recoil and we show a convincing signal but only slightly more than 1 sigma from 0. In order to reach quantitatively significant results we plan to exploit fully smaller lattice spacings as well as another lattice regularisation.

Description: We present a simulation study of the prospects for the mass measurement of TeV-scale light-flavored right-handed squarks at a 3 TeV \(e^+e^-\) collider based on CLIC technology. In the considered model, these particles decay into their standard-model counterparts and the lightest neutralino, resulting in a signature of two jets plus missing energy. The analysis is based on full GEANT4 simulations of the CLIC_ILD detector concept, including Standard Model physics backgrounds and beam-induced hadronic backgrounds from two-photon processes. The analysis serves as a generic benchmark for the reconstruction of highly energetic jets in events with substantial missing energy. Several jet finding algorithms were evaluated, with the longitudinally invariant \(k_t\) algorithm showing a high degree of robustness towards beam-induced background while preserving the features typically found in algorithms developed for \(e^+e^-\) collisions. The presented study of the reconstruction of light-flavored squarks shows that for TeV-scale squark masses, sub-percent accuracy on the mass measurement can be achieved at CLIC.

Description: We evaluate the Hadamard function and the vacuum expectation value (VEV) of the current density for a charged scalar field, induced by flat boundaries in spacetimes with an arbitrary number of toroidally compactified spatial dimensions. The field operator obeys the Robin conditions on the boundaries and quasiperiodicity conditions with general phases along compact dimensions. In addition, the presence of a constant gauge field is assumed. The latter induces Aharonov–Bohm-type effect on the VEVs. There is a region in the space of the parameters in Robin boundary conditions where the vacuum state becomes unstable. The stability condition depends on the lengths of compact dimensions and is less restrictive than that for background with trivial topology. The vacuum current density is a periodic function of the magnetic flux, enclosed by compact dimensions, with the period equal to the flux quantum. It is explicitly decomposed into the boundary-free and boundary-induced contributions. In sharp contrast to the VEVs of the field squared and the energy-momentum tensor, the current density does not contain surface divergences. Moreover, for Dirichlet condition it vanishes on the boundaries. The normal derivative of the current density on the boundaries vanish for both Dirichlet and Neumann conditions and is nonzero for general Robin conditions. When the separation between the plates is smaller than other length scales, the behavior of the current density is essentially different for non-Neumann and Neumann boundary conditions. In the former case, the total current density in the region between the plates tends to zero. For Neumann boundary condition on both plates, the current density is dominated by the interference part and is inversely proportional to the separation.

Description: A small tensor-to-scalar ratio r may lead to distinctive phenomenology of high-scale supersymmetry. Assuming the same origin of SUSY breaking between the inflation and visible sector, we show model independent features. The simplest hybrid inflation, together with a new linear term for the inflaton field which is induced by a large gravitino mass, is shown to be consistent with all experimental data for r of order \(10^{-5}\) . For superpartner masses far above the weak scale we find that the reheating temperature after inflation might be below the value required by thermal leptogenesis if the inflaton decays to its products perturbatively, but above it if the decay is non-perturbatively instead. Remarkably, the gravitino overproduction can be evaded in such high-scale supersymmetry because of the kinematically blocking effect.

Description: We show how leading radiative corrections can be implemented in the general description of \(h\rightarrow 4\ell \) decays by means of pseudo observables (PO). With the inclusion of such corrections, the PO description of \(h\rightarrow 4\ell \) decays can be matched to next-to-leading-order electroweak calculations both within and beyond the Standard Model (SM). In particular, we demonstrate that with the inclusion of such corrections the complete next-to-leading-order SM prediction for the \(h\rightarrow 2e2\mu \) dilepton mass spectrum is recovered within \(1\,\%\) accuracy. The impact of radiative corrections for non-standard PO is also briefly discussed.

Description: A comprehensive review of physics at an \(e^+e^-\) linear collider in the energy range of \(\sqrt{s}=92\)  GeV–3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

Description: The drivers in actual traffic differ in the aggressiveness in driving behaviors, which will finally be reflected in the interaction between vehicles and fluctuations in flows. In this paper, we try to study the effect of driving aggressiveness on the traffic stability by proposing an extended microscopic car-following model, in which the optimal velocity is reconstructed to divide the drivers in traffic system into two groups according to driving aggressiveness of each individual. The stability condition of the proposed model is derived to explore its ability against a small perturbation by use of the linear stability theory. We obtain the neutral stability lines for different percentages of drivers with a higher driving aggressiveness, finding that the traffic flow trends to stable with the increase in the percentage for higher driving aggressiveness drivers when the average headway is less than a critical value or greater than another critical value, but when the average headway falls into the intermediate range between the two critical values, the traffic flow becomes more and more unstable with increase in the percentage of drivers with a higher driving aggressiveness. Finally, numerical simulations are conducted to verify these theoretical results and examine how the percentage of vehicles driven by higher driving aggressiveness drivers affects the traffic flux of the vehicle system.

Description: This paper investigates adaptive synchronization of stochastic time-varying delay dynamical networks with complex-variable systems. By using the complex inequality, stochastic analysis theory and two kinds of random disturbances, several sufficient conditions to ensure adaptive synchronization for stochastic time-varying delay networks with complex-variable systems. To illustrate the effectiveness of the synchronization conditions derived in this paper, numerical examples are provided finally.

Description: This paper presents the unified cooperative strategies for the salvo attack of multiple missiles on the basis of the traditional proportional navigation (PN) algorithm. The cooperative guidance laws are developed in a quite simple formulation consisting of a PN component for target capture and a coordination component for simultaneous arrival. The centralized coordination algorithms have better performance when the global information of time-to-go can be obtained by each missile, whereas the decentralized coordination algorithms come into effect when the group member is only able to collect information from its neighbors. The cooperative strategies can achieve a simultaneous attack against both stationary and maneuvering targets. Numerical simulations are used to demonstrate that the proposed approaches are feasible and flexible for the salvo attack of multiple missiles. The capturability analyses of the cooperative guidance laws are also performed by discussing the selection of gain parameters.

Description: In this work we complete the integrability conditions (i.e., conditions for the existence of a local analytic first integral) for a family of a resonant saddle perturbed with homogeneous quintic nonlinearities studied in a previous work. In order to obtain the necessary conditions we use modular arithmetic computations.

Description: The chaotic behavior of the secondary asteroid in a system of binary asteroids due to the asphericity and orbital eccentricity is investigated analytically and numerically. The binary asteroids are modeled with a sphere–ellipsoid model, in which the secondary asteroid is ellipsoid. The first-order resonance is studied for different values of asphericity and eccentricity of the secondary asteroid. The results of the Chirikov method are verified by Poincare section which show good agreement between analytical and numerical methods. It is also shown that asphericity and eccentricity affect the size of resonance regions such that beyond the threshold value, the resonance overlapping occurs and widespread chaos is visible.

Description: An efficient and secure three-party authenticated key agreement protocol is proposed to enable two users to establish a common secret key for exchanging confidential and authenticated information with the help of a trusted server. The proposed protocol only employs extended chaotic maps and hash operations, i.e., it does not require a server public key, symmetric cryptosystems, time-consuming modular exponential computations, or time-consuming modular exponential computations and scalar multiplications on elliptic curve. A round-efficient version of the proposed protocol is also implemented by rearranging and sending the messages in parallel. The session security of the proposed protocol is based on the Chebyshev chaotic map-based Diffie–Hellman assumption. Compared to related chaotic map-based approaches, the proposed protocol not only requires lower computational cost, but also has fewer transmissions.

Description: We investigate the fragmentation instability of hairy black holes in the theory with a Gauss–Bonnet (GB) term in asymptotically flat spacetime. Our approach is through the non-perturbative fragmentation instability. By this approach, we investigate whether the initial black hole can be broken into two black holes by comparing the entropy of the initial black hole with the sum of those of two fragmented black holes. The relation between the black hole instability and the GB coupling with dilaton hair are presented. We describe the phase diagrams with respect to the mass of the black hole solutions and coupling constants. We find that a perturbatively stable black hole can be unstable under fragmentation.

Description: A pulse-shape discrimination method based on artificial neural networks was applied to pulses simulated for different background, signal and signal-like interactions inside a germanium detector. The simulated pulses were used to investigate variations of efficiencies as a function of used training set. It is verified that neural networks are well-suited to identify background pulses in true-coaxial high-purity germanium detectors. The systematic uncertainty on the signal recognition efficiency derived using signal-like evaluation samples from calibration measurements is estimated to be 5 %. This uncertainty is due to differences between signal and calibration samples.

Description: In this paper, a novel adaptive neural network control approach is presented for a class of uncertain discrete-time nonlinear strict-feedback systems with input saturation. By combining single neural network approximation and minimal learning parameter technique, the proposed approach is able to eliminate the complexity growing problem and alleviate the explosion of learning parameters. An auxiliary design system is incorporated into the control scheme to overcome the problem of input saturation constraints. Following this approach, the designed controller contains only one actual control law and one adaptive law, the numbers of input variables and weights of neural network updated online are decreased drastically, and the number of parameter updated online for whole system is reduced to only one. Compared with the existing methods, the adaptive mechanism with much simpler controller structure and minimal learning parameterization is achieved; therefore, the computational burden is lighter. It is shown via Lyapunov theory that all signals in the closed-loop system are uniformly ultimately bounded. Finally, simulation results via two examples are employed to illustrate the effectiveness and merits of the proposed scheme.

Description: This paper investigates the problem of global coordinated tracking of a multi-agent system with input additive uncertainties and disturbances via bounded control inputs. Scheduled low-and-high gain feedback-based distributed coordinated tracking protocols are developed. It is shown that, under the assumptions that each agent is asymptotically null controllable with bounded controls and the network is connected, global coordinated tracking of the multi-agent system can be achieved. We finally show some numerical simulations to verify and illustrate the theoretical results.

Description: In this paper, a four-neuron delayed system with inertial terms is considered. By studying the distribution of the eigenvalues of the associated characteristic equation, we derive the critical values where double Hopf bifurcation occurs. Then by employing the perturbation-incremental scheme for the system, bifurcation diagrams are obtained. Furthermore, we carry out bifurcation analysis showing that there exist a stable fixed point, two stable periodic solutions, co-existence of a pair of stable periodic solutions and quasi-periodic motion in the neighborhood of the double Hopf critical point. We also find some interesting phenomena that the dynamical period switching occurs in some delayed regions. Finally, some numerical simulations are performed to support the theoretical analysis.

Description: Analytical spatiotemporal soliton solutions of the coupled nonlinear Schrödinger equation are derived in the (3  \(+\)  1)-dimensional inhomogeneous \(\mathcal {PT}\) -symmetric nonlinear couplers by means of the Hirota bilinear method. Based on these analytical solutions, we construct abundant spatiotemporal soliton structures and discuss the expansion and compression behaviors of spatiotemporal soliton structures in a periodic modulation system.

Description: In this paper we develop a systematic and self-consistent procedure based on a set of compatibility conditions for identifying all maximal (eight parameter) and non-maximal (one and two parameter) symmetry groups associated with the mixed quadratic-linear Liénard-type equation, \(\ddot{x} + f(x){\dot{x}}^{2} + g(x)\dot{x}+h(x)= 0\) , where \(f(x),\,g(x)\) and h ( x ) are arbitrary functions of x . With the help of this procedure we show that a symmetry function b ( t ) is zero for non-maximal cases, whereas it is not so for the maximal case. On the basis of this result the symmetry analysis gets divided into two cases, (i) the maximal symmetry group \((b\ne 0)\) and (ii) non-maximal symmetry groups \((b=0)\) . We then identify the most general form of the mixed quadratic linear Liénard-type equation in each of these cases. In the case of eight-parameter symmetry group, the identified general equation becomes linearizable. In the case of non-maximal symmetry groups the identified equations are all integrable. The integrability of all the equations is proved either by providing the general solution or by constructing time-independent Hamiltonians.

Description: This paper reveals the dynamical behaviors of a coupled network consisting of four neural sub-networks and multiple two-way couplings of neurons between the individual sub-networks. Different types of time delays are introduced into the internal connections within the individual sub-networks and the couplings between the sub-networks. Stability switches of the network equilibrium and Hopf bifurcation are analyzed by discussing the associated characteristic equation. The conditions for the existence of different patterns of oscillations are discussed. By using the Lyapunov’s second method, the global stability of the network equilibrium is studied. Numerical simulations are performed to validate the theoretical results, and rich dynamical behaviors are observed, such as synchronous oscillations, multiple stability switches between the rest state and oscillations, phase-locked oscillations, asynchronous oscillations, and the coexistence of different patterns of bifurcated oscillations.

Description: A significant impediment to the deployment of vibration-based energy harvesting devices has been the limitation of most low-frequency transducers, usually in the form of unimorph or bimorph cantilever beam, to extract energy from a very narrow bandwidth around the transducer’s fundamental frequency. In such devices, a slight deviation from the fundamental frequency causes a significant reduction in the level of harvested power by several orders of magnitudes. Additionally, most of the current research efforts on the design of piezoelectric energy harvesters have had limited success in achieving low resonance frequency. To overcome these challenges, we introduce an enhanced broadband low-frequency piezomagnetoelastic energy harvester. This harvester consists of a partially covered piezoelectric cantilever beam with a fixed magnet mass at the top of the magnet tip mass. A nonlinear distributed-parameter model based on Euler–Bernoulli beam theory and Galerkin discretization is developed. This electromechanical model is validated with previous experimental measurements for a specific value of the spacing distance between the two magnets. A parametric study is performed to determine the effects of the spacing distance between the two magnets on the static position of the harvester, natural frequency, and level of the harvested power. It is demonstrated that a decrease between the two attractive magnets results in a decrease in the natural frequency of the harvester with a strong softening behavior which gives the opportunity to harvest energy at broadband low-frequency range. The results also show that the presence and importance of the softening behavior depends on the electrical load resistance. In conclusion, the results show that depending on the available low excitation frequency, an enhanced piezoelectric energy harvester can be tuned and optimized by changing the spacing distance between the two tip magnets.

Description: In this article, we calculate the form factors and the coupling constant of the vertex \(D_{s}^{*}D_{s}\phi \) using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension 7 in the operator product expansion. And all possible off-shell cases are considered, \(\phi \) , \(D_{s}\) and \(D_{s}^{*}\) , resulting in three different form factors. Then we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant for the process. Our analysis indicates that the coupling constant for this vertex is \(G_{D_{s}^{*}D{_{s}}\phi }=4.12\pm 0.70\,\mathrm{GeV}^{-1}\) . The results of this work are very useful in the other phenomenological analysis. As an application, we calculate the coupling constant for the decay channel \(D_{s}^{*}\rightarrow D_{s}\gamma \) and analyze the width of this decay with the assumption of the vector meson dominance of the intermediate \(\phi (1020)\) . Our final result about the decay width of this decay channel is \(\Gamma =0.59\pm 0.15\,\mathrm{keV}\) .

Description: In this paper, we are interested to justified two typical hypotheses that appear in the convergence analysis, \(|\lambda |\le 2\) and \(z_0\) sufficient close to \(z^*\) . In order to proof these ideas, the dynamics of a damped two-step Newton-type method for solving nonlinear equations and systems is presented. We present the parameter space for values of the damping factor in the complex plane, focusing our attention in such values for which the fixed points related to the roots are attracting. Moreover, we study the stability of the strange fixed points, showing that there exists attracting cycles and chaotical behavior for some choices of the damping factor.

Description: We consider memelements (memristors and memductors) with special periodic responses (mixed-mode oscillations) and 2D one-period loops yielding constant parameters describing the memelements as single units or components of oscillating circuits. One of the parameters is the action parameter having the dimensions of energy   \(\times \)   time and the SI unit Joule   \(\times \)   second . The remaining loops and parameters correspond to energy of magnetic and electric fields, power and rms current and voltage values. Special mixed one-period loops are also analyzed with pairs of signals associated with two different components of the circuits. The areas enclosed by various loops result in special equations which can be derived from the underlying ODE model of the circuits. The action of a memelement is equivalent to the time integral of the Lagrangian \(L(w,w')\) , where w is the internal state variable of a memelement. The analysis of memristive circuits and their parameters is considered in the framework of mixed-mode oscillations. Also, the unit of action for memelements is proposed to be called Chua ( \(=\) Joule \(\,\times \)   second ) to honor L.O. Chua for his work on memristors and memristive circuits.

Description: In this paper, the binary Bell polynomials are employed to find the bilinear form, bilinear Bäcklund transformation and Lax pair for the (3+1)-dimensional BKP equation. Based on Hirota’s bilinear form and three-wave method, multi-soliton solutions are presented. Furthermore, a new bilinear Bäcklund transformation is constructed via applying a gauge transformation to the Bäcklund transformation in bilinear form.

Description: In this paper, a \((2 + 1)\) -dimensional generalized shallow water wave equation is investigated through bilinear Hirota method. Interestingly, the breather-type and lump-type soliton solutions are obtained. Furthermore, dynamic properties of the soliton waves are revealed by means of the asymptotic analysis. Based on Hirota bilinear method and Riemann theta function, we succeed in constructing quasi-periodic wave solutions with a generalized form. We also display the asymptotic properties of these quasi-periodic wave solutions and point out the relation between the quasi-periodic wave solutions and the soliton solutions.

Description: Extensive N -body simulations are among the key means for the study of numerous astrophysical and cosmological phenomena, so various schemes are developed for possibly higher accuracy computations. We demonstrate the principal possibility for revealing the evolution of a perturbed Hamiltonian system with an accuracy independent on time. The method is based on the Laplace transform and the derivation and analytical solution of an evolution equation in the phase space for the resolvent and using computer algebra.

Description: A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5 \(\,\text {fb}^\text {-1}\) collected by the CMS experiment at the LHC in \(\mathrm {p}\mathrm {p}\) collisions at a centre-of-mass energy of 8 \(\,\hbox {TeV}\) . In order to separate the signal from the larger \(\hbox {t}\overline{\hbox {t}}\)  + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, \(\mu \) , relative to the standard model prediction for a Higgs boson mass of 125 \(\,\hbox {GeV}\) . The observed (expected) exclusion limit at a 95 % confidence level is \(\mu 〈4.2\) (3.3), corresponding to a best fit value \(\hat{\mu }=1.2^{+1.6}_{-1.5}\) .

Description: In this paper we are concerned with the effects of an anisotropic pressure on the boundary conditions of the anisotropic Lane–Emden equation and the homology theorem. Some new exact solutions of this equation are derived. Then some of the theorems governing the Newtonian perfect fluid star are extended, taking the anisotropic pressure into account.

Description: An optimized digital shaping filter has been developed for the Gerda experiment which searches for neutrinoless double beta decay in \(^{76}\) Ge. The Gerda Phase I energy calibration data have been reprocessed and an average improvement of 0.3 keV in energy resolution (FWHM) corresponding to 10 % at the \(Q\) value for \(0\nu \beta \beta \) decay in \(^{76}\) Ge is obtained. This is possible thanks to the enhanced low-frequency noise rejection of this Zero Area Cusp (ZAC) signal shaping filter.

Description: A generalisation of the narrow-width approximation (NWA) is formulated which allows for a consistent treatment of interference effects between nearly mass-degenerate particles in the factorisation of a more complicated process into production and decay parts. It is demonstrated that interference effects of this kind arising in BSM models can be very large, leading to drastic modifications of predictions based on the standard NWA. The application of the generalised NWA is demonstrated both at tree level and at one-loop order for an example process where the neutral Higgs bosons h and H of the MSSM are produced in the decay of a heavy neutralino and subsequently decay into a fermion pair. The generalised NWA, based on on-shell matrix elements or their approximations leading to simple weight factors, is shown to produce UV- and IR-finite results which are numerically close to the result of the full process at tree level and at one-loop order, where an agreement of better than \(1\,\%\) is found for the considered process. The most accurate prediction for this process based on the generalised NWA, taking into account also corrections that are formally of higher orders, is briefly discussed.

Description: A new theory of gravity called Eddington-inspired Born–Infeld (EiBI) gravity was recently proposed by Bañados and Ferreira. This theory leads to some exciting new features, such as free of cosmological singularities. In this paper, we first obtain a charged EiBI black hole solution with a nonvanishing cosmological constant when the electromagnetic field is included in. Then based on it, we study the strong gravitational lensing by the asymptotic flat charged EiBI black hole. The strong deflection limit coefficients and observables are shown to closely depend on the additional coupling parameter \(\kappa \) in the EiBI gravity. It is found that, compared with the corresponding charged black hole in general relativity, the positive coupling parameter \(\kappa \) will shrink the black hole horizon and photon sphere. Moreover, the coupling parameter will decrease the angular position and relative magnitudes of the relativistic images, while increase the angular separation, which may shine new light on testing such gravity theory in near future by the astronomical instruments.

Description: In this paper, the classical problem and the inverse problem of generalized synchronization for different dimensional chaotic dynamical systems in discrete time are investigated. The generalized synchronization results have been derived using active control method and Lyapunov stability theory. Numerical simulations are performed to verify the effectiveness of the proposed schemes.

Description: Under investigation in this paper is a generalized \((2+1)\) -dimensional Korteweg–de Vries equation, which could describe many nonlinear phenomena in plasma physics. By virtue of the Bell’s polynomials, a straightforward way is presented to succinctly construct its bilinear form, bilinear Bäcklund transformation and Lax pairs. Once the Lax pairs obtained, the important infinite conservation laws of the equation are directly found. Moreover, based on the bilinear formalism, we construct the Riemann theta function periodic wave solutions and soliton solutions. Finally, the relationships between the periodic wave solutions and soliton solutions are strictly established, and the asymptotic behavior of the periodic waves is also presented with detailed proof.

Description: This manuscript is devoted to the investigation of the Bianchi type I universe in the context of f ( R ,  T ) gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type I spacetime. The modified field equations are solved by assuming an expansion scalar \(\theta \) proportional to the shear scalar \(\sigma \) , which gives \(A=B^n\) , where A ,   B are the metric coefficients and n is an arbitrary constant. In particular, three solutions have been found and physical quantities are calculated in each case.

Description: By detecting redshift drift in the spectra of the Lyman- \(\alpha \) forest of distant quasars, the Sandage–Loeb (SL) test directly measures the expansion of the universe, covering the “redshift desert” of \(2 \lesssim z \lesssim 5\) . Thus this method is definitely an important supplement to the other geometric measurements and will play a crucial role in cosmological constraints. In this paper, we quantify the ability of the SL test signal by a CODEX-like spectrograph for constraining interacting dark energy. Four typical interacting dark energy models are considered: (i) \(Q=\gamma H\rho _c\) , (ii) \(Q=\gamma H\rho _{de}\) , (iii) \(Q=\gamma H_0\rho _c\) , and (iv) \(Q=\gamma H_0\rho _{de}\) . The results show that for all the considered interacting dark energy models, relative to the current joint SN  \(+\)  BAO  \(+\)  CMB  \(+\)   \(H_0\) observations, the constraints on \(\Omega _m\) and \(H_0\) would be improved by about 60 and 30–40 %, while the constraints on w and \(\gamma \) would be slightly improved, with a 30-year observation of the SL test. We also explore the impact of the SL test on future joint geometric observations. In this analysis, we take the model with \(Q=\gamma H\rho _c\) as an example, and we simulate future SN and BAO data based on the space-based project WFIRST. We find that with the future geometric constraints, the redshift drift observations would help break the geometric degeneracies in a meaningful way, thus the measurement precisions of \(\Omega _m\) , \(H_0\) , w , and \(\gamma \) could be substantially improved using future probes.

Description: To identify the nature of the newly observed charged resonance \(Z_c(4200)^+\) , we study its hadronic decays \(Z_c(4200)^+\rightarrow J/\psi \pi ^+, Z_c(4200)^+\rightarrow \eta _c\rho ^+\) and \(Z_c(4200)^+\rightarrow D^+\bar{D}^{*0}\) as a charmonium-like tetraquark state. In the framework of the QCD sum rules, we calculate the three-point functions and extract the coupling constants and decay widths for these interaction vertices. Including all these channels, the full decay width of the \(Z_c(4200)^+\) state is consistent with the experimental value reported by the Belle Collaboration, supporting the tetraquark interpretation of this state.

Description: In the present paper, we study regular and chaotic dynamics from planar oscillations of a dumbbell satellite under the influence of the gravity field generated by an oblate body, considering the effect of the zonal harmonic parameter \(J_{2}\) . We theoretically show the existence of chaotic oscillations provided that the eccentricity becomes arbitrarily small, and the parameter \(J_{2}\) is of the same order of magnitude as the eccentricity. This is carried out by applying the so-called Melnikov method. Finally, for arbitrarily chosen values for the parameters involved in such a problem, we study the transition from regular to chaotic oscillations for a dumbbell satellite via the analysis of chaotic maps and Poincaré surfaces of section, respectively.

Description: We obtain some results on transitivity for cyclically permuted direct product maps, that is, maps of the form \(F\left( x_{1},x_{2},\ldots ,x_{n}\right) =\left( f_{\sigma (1)}\left( x_{\sigma (1)}\right) ,f_{\sigma (2)}\left( x_{\sigma (2)}\right) ,\ldots ,f_{\sigma (n)}\left( x_{\sigma (n)}\right) \right) \) , defined from the Cartesian product \(I^n\) onto itself, where \(I=[0,1]\) , \(\sigma \) is a cyclic permutation of \(\{1,2,\ldots ,n\}\) \((n\ge 2)\) and each map \(f_{\sigma (j)}:I\rightarrow I\) is continuous, \(j\in \{1,\ldots ,n\}\) . In particular, we prove that for \(n\ge 3\) the transitivity of F is equivalent to the total transitivity, and if \(n=2\) , we give a splitting result for transitive maps. Moreover, we extend well-known properties of transitivity from interval maps to cyclically permuted direct product maps. To do it, we use the strong link between F and the compositions \(\varphi _j=f_{\sigma (j)}\circ \ldots \circ f_{\sigma ^n(j)},\, j\in \{1,\ldots ,n\}.\)

Description: A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2012 at \(\sqrt{s}=8\)  TeV from pp collisions corresponding to an integrated luminosity of 20.3 fb \(^{-1}\) are examined. Particles producing anomalously high ionisation, consistent with long-lived massive particles with electric charges from \(|q|=2e\) to \(|q|=6e\) are searched for. No signal candidate events are observed, and 95 % confidence level cross-section upper limits are interpreted as lower mass limits for a Drell–Yan production model. The mass limits range between 660 and 785 GeV.

Description: In this paper, targeted energy transfer from a nonlinear continuous system to a nonlinear energy sink (NES) is investigated. For this purpose, the equation of a nonlinear beam with simply supported ends, on which the NES is attached, is derived using Rayleigh–Ritz method and the Lagrange equation. Then, parameters of the NES are optimized by both sensitivity analysis and particle swarm optimization (PSO) method. Analysis of the energy transfer between the nonlinear beam and the NES is presented, using the complexification-averaging method, too. Attaching an NES to a nonlinear continuous system and using the PSO method to obtain the optimized parameters of the NES is a new development, presented in this work. Also, here, more than one mode of the beam has been considered for analysis of energy transfer between the NES and different modes of the primary system.

Description: In this work we present a pseudo-random Bit Generator via unidimensional multi-modal discrete dynamical systems called k -modal maps. These multi-modal maps are based on the logistic map and are useful to yield pseudo-random sequences with longer period, i.e., in order to attend the problem of periodicity. In addition the pseudo-random sequences generated via multi-modal maps are evaluated with the statistical suite of test from NIST and satisfactory results are obtained when they are used as key stream. Furthermore, we show the impact of using these sequences in a stream cipher resulting in a better encryption quality correlated with the number of modals of the chaotic map. Finally, a statistical security analysis applied to cipher images is given. The proposed algorithm to encrypt is able to resist the chosen-plaintext attack and differential attack because the same set of encryption keys generates a different cipher image every time it is used.

Description: We study to which extent SUSY extensions of the Standard Model can describe the excess of events of 3.0 standard deviations observed by ATLAS in the on- Z signal region, respecting constraints by CMS on similar signal channels as well as constraints from searches for jets and \(E^\mathrm{miss}_\text {T}\) . GMSB-like scenarios are typically in conflict with these constraints, and do not reproduce well the shape of the \(E^\mathrm{miss}_\text {T}\) distribution of the data. An alternative scenario with two massive neutralinos can improve fits to the total number of events as well as to the \(H_\text {T}\) and \(E^\mathrm{miss}_\text {T}\) distributions. Such a scenario can be realised within the NMSSM.

Description: Leading-twist operators have a remarkable property that their divergence vanishes in a free theory. Recently it was suggested that this property can be used for an alternative technique to calculate anomalous dimensions of leading-twist operators and allows one to gain one order in perturbation theory so that, i.e., two-loop anomalous dimensions can be calculated from one-loop Feynman diagrams, etc. In this work we study the feasibility of this program by a toy-model example of the \(\varphi ^3\) theory in six dimensions. Our conclusion is that this approach is valid, although it does not seem to present considerable technical simplifications as compared to the standard technique. It does provide one, however, with a very nontrivial check of the calculation as the structure of the contributions is very different.

Description: Recently, a family of interesting analytical brane solutions were found in f ( R ) gravity with \(f(R)=R \,+\, \alpha R^2\) in Bazeia et al. (Phys Lett B 729:127 2014 ). In these solutions, the inner brane structure can be turned on by tuning the value of the parameter \(\alpha \) . In this paper, we investigate how the parameter \(\alpha \) affects the localization and the quasilocalization of the tensorial gravitons around these solutions. It is found that, in a range of \(\alpha \) , despite the brane having an inner structure, there is no graviton resonance. However, in some other regions of the parameter space, although the brane has no internal structure, the effective potential for the graviton Kaluza–Klein (KK) modes has a singular structure, and there exist a series of graviton resonant modes. The contribution of the massive graviton KK modes to Newton’s law of gravity is discussed briefly.

Description: The production of the Standard Model Higgs boson in association with a vector boson, followed by the dominant decay to \(H \rightarrow b\bar{b}\) , is a strong prospect for confirming and measuring the coupling to b -quarks in pp collisions at \(\sqrt{s}=14\)  TeV. We present an updated study of the prospects for this analysis, focussing on the most sensitive highly Lorentz-boosted region. The evolution of the efficiency and composition of the signal and main background processes as a function of the transverse momentum of the vector boson are studied covering the region 200–1000 GeV, comparing both a conventional dijet and jet substructure selection. The lower transverse momentum region (200–400 GeV) is identified as the most sensitive region for the Standard Model search, with higher transverse momentum regions not improving the statistical sensitivity. For much of the studied region (200–600 GeV), a conventional dijet selection performs as well as the substructure approach, while for the highest transverse momentum regions ( \(〉\) 600 GeV), which are particularly interesting for Beyond the Standard Model and high luminosity measurements, the jet substructure techniques are essential.

Description: Massive QED, in contrast with its massless counterpart, possesses two conserved charges; one is a screened (vanishing) Maxwell charge which is directly associated with the massive vector mesons through the identically conserved Maxwell current, while the presence of a particle-antiparticle counting charge depends on the matter. A somewhat peculiar situation arises for couplings of Hermitian matter fields to massive vector potentials; in that case the only current is the screened Maxwell current and the coupling disappears in the massless limit. In the case of self-interacting massive vector mesons the situation becomes even more peculiar in that the usually renormalizability guaranteeing validity of the first order power-counting criterion breaks down in second order and requires the compensatory presence of additional Hermitian H -fields. Some aspect of these observation have already been noticed in the BRST gauge theoretic formulation, but here we use a new setting based on string-local vector mesons which is required by Hilbert space positivity (“off-shell unitarity”). This new formulation explains why spontaneous symmetry breaking cannot occur in the presence of higher spin \(s\ge 1\)  fields. The coupling to H -fields induces Mexican hat-like self-interactions; they are not imposed and bear no relation with spontaneous symmetry breaking; they are rather consequences of the foundational causal localization properties realized in a Hilbert space setting. In the case of self-interacting massive vector mesons their presence is required in order to maintain the first order power-counting restriction of renormalizability also in second order. The presentation of the new Hilbert space setting for vector mesons which replaces gauge theory and extends on-shell unitarity to its off-shell counterpart is the main motivation for this work. The new Hilbert space setting also shows that the second order Lie-algebra structure of self-interacting vector mesons is a consequence of the principles of QFT and promises a deeper understanding of the origin of confinement.

Description: We develop a methodology for the construction of a Hessian representation of Monte Carlo sets of parton distributions, based on the use of a subset of the Monte Carlo PDF replicas as an unbiased linear basis, and of a genetic algorithm for the determination of the optimal basis. We validate the methodology by first showing that it faithfully reproduces a native Monte Carlo PDF set (NNPDF3.0), and then, that if applied to Hessian PDF set (MMHT14) which was transformed into a Monte Carlo set, it gives back the starting PDFs with minimal information loss. We then show that, when applied to a large Monte Carlo PDF set obtained as combination of several underlying sets, the methodology leads to a Hessian representation in terms of a rather smaller set of parameters (MC-H PDFs), thereby providing an alternative implementation of the recently suggested Meta-PDF idea and a Hessian version of the recently suggested PDF compression algorithm (CMC-PDFs). The mc2hessian conversion code is made publicly available together with (through LHAPDF6 ) a Hessian representations of the NNPDF3.0 set, and the MC-H PDF set.

Description: We explore a fermionic dark matter model with a possible extension of Standard Model of particle physics into two Higgs doublet model. Higgs doublets couple to the singlet fermionic dark matter through a non-renormalisable coupling providing a new physics scale. We explore the viability of such dark matter candidate and constrain the model parameter space by collider serach, relic density of DM, direct detection measurements of DM-nucleon scattering cross-section and with the experimentally obtained results from indirect search of dark matter.

Description: In this paper, we numerically study the effect of ion channel noise on the synchronization of delayed Newman–Watts network of stochastic Hodgkin–Huxley neurons. It is found that time delay can induce synchronization transitions only when channel noise intensity is intermediate, and the synchronization transitions become most obvious when channel noise intensity is optimal. As channel noise intensity is varied, the neurons can also exhibit synchronization transitions, and the phenomenon is enhanced when time delay is tuned at around time delays that can induce synchronization transitions. Moreover, this phenomenon becomes most obvious when the value of coupling strength or the value of network randomness is optimal. These results show that channel noise has a subtle regulation effect on the synchronization of the neuronal network. These findings may find potential implications for the normal and pathological functions in the brain and the information processing and transmission in neural systems.

Description: Using the tool of Turing instability for partial differential equations, we investigate the spatiotemporal distributions for solutions of a predator–prey-type reaction–diffusion model with spatiotemporal delay. The linear stability conditions of Turing instability, which induce bifurcation patterns in this model, are obtained. Moreover, according to these conditions, we numerically calculate the bifurcation diagrams by using time delay and the predator rate as parameters. The effects of two parameters in the different bifurcation diagrams are also demonstrated through numerical computations and lead to some spatiotemporal patterns of this model, which enrich the pattern formation of predator–prey models.

Description: A new two-lane traffic lattice hydrodynamic model is proposed with the consideration of the global average-and-optimal flux difference effect based on the local relative flux two-lane lattice model. First, the influence of the global average-and-optimal flux difference on the stability of traffic flow is investigated through linear stability theory. The results reveal that the unstable region will be shrunk by taking the global average-and-optimal flux difference effect into account. Additionally, by using the reductive perturbation method, the mKdV equation near the critical point is derived and traffic jam transition can be described by its kink–antikink soliton solution. The good agreement between the numerical simulations and the analytical results shows that traffic congestion can be suppressed efficiently by considering the global average-and-optimal flux difference and the local relative flux effects in two-lane traffic system and the local relative flux is more important than the global average-and-optimal flux difference in stabilizing traffic flow.

Description: Under investigation in this paper is a \((2+1)\) -dimensional Korteweg–de Vries-type equation, which can describe the propagation of nonlinear waves such as the shallow-water waves, surface and internal waves. By virtue of the Bell polynomials, symbolic computation and auxiliary independent variable, the bilinear forms, Bäcklund transformations and soliton solutions are obtained. Solitonic propagation and elastic collisions between/among the two- and three-solitons are discussed analytically and graphically. It can be seen that, after each collision, solitonic shapes and amplitudes keep invariant except for some phase shifts, and the smaller-amplitude soliton moves faster and overtakes the larger.

Description: An overview of the flavour problem is presented, with emphasis on the theoretical efforts to find a satisfactory description of the fermion masses and the mixing angles.

Description: Based on the optimal velocity model, a new continuum model considering traffic jerk effect is presented in this paper. Then, the critical condition for the steady traffic flow is deduced. Near the neutral stability line, nonlinear analysis is taken to derive the KdV-Burgers equation for describing the density wave, and one of the solutions is given. Numerical simulation is carried out to study the influence about the traffic jerk effect.

Description: The nonlinear dynamical behavior of the hysteretic rheological device proposed in Carboni et al. (J Eng Mech 2014 ) is investigated. The device can provide nonlinear hysteretic forces to a one-degree-of-freedom (one-dof) mass through suitable assemblies of NiTiNOL and steel wire ropes subject to tension–flexure cycles. The simultaneous occurrence of interwire friction, phase transformations and geometric nonlinearities is the key feature of the obtained material behavior. Frequency-response curves (FRCs) of the system subject to base excitation are obtained numerically via a continuation procedure together with stability analysis and experimentally by carrying out shaking table tests, respectively. The phenomenological identification of the material behaviors through force–displacement cycles, reported in Carboni et al. (J Eng Mech 2014 ), is employed for the computation of the FRCs and the equivalent damping ratios as function of the displacement amplitude. The different restoring forces give rise to whole new families of nonlinear hysteretic oscillators governed by softening, hardening and softening–hardening behaviors depending on the oscillation amplitude.

Description: The modeling of the piezoelectric actuator is very important for the fast and accurate nano-positioning control. However, the complex creep, vibration and hysteresis dynamics make the modeling very difficult. Because there are often model uncertainties in the first-principle model, the model identification from the experimental data is very necessary. Most identification approaches only consider partial dynamics of the creep, vibration and hysteresis. Though they can be combined together after they are individually identified from different experiments, it is difficult to design the completely decoupled experiment. In this study, an incremental Hammerstein-like modeling approach is proposed to identify the creep, vibration and hysteresis dynamics from one experiment. The model is called nonlinear–linear–linear-Hammerstein-like model, where one dynamic nonlinear system is used to model the hysteresis and two dynamic linear systems are used to model the creep and vibration. The creep and vibration are assumed to be decoupled, and there is a known upper bound on the order of the creep model. A two-stage incremental modeling approach is proposed to reduce the modeling complexity, where the slow dynamics of the hysteresis and creep are estimated first and then the residual of this model is used to estimate the fast dynamics of the vibration. In each stage, the model structure and order are determined by a locally regularized orthogonal least-squares-based model term selection algorithm and the parameters are estimated using a regularized least-squares method. The effectiveness of the proposed modeling approach is verified by the simulations and experiments on typical piezoelectric actuators.

Description: This paper investigates the problem of harvesting energy from transverse base vibration by a laminated piezoelectric beam. The beam is fixed at one end and subjected to a compressive load at the other end. The electromechanical model is set up, and the corresponding equations are derived by extended Hamilton principle. The simulation is carried out, and the results are obtained. The response under harmonic excitation exhibits that the system experiences period-doubling bifurcation and chaos as frequency varies, and the buckled state can generate more power compared to the unbuckled one. Coherence resonance is proved and can be observed when the system is subjected to Gauss white noise excitation, which can be used to optimize the efficiency of energy harvesting.

Description: In this paper, we present a new scheme for the secured transmission of discrete information based on hyperchaotic discrete dynamics. The system is a modified-Henon hyperchaotic discrete-time oscillator considered as transmitter and a delayed step-by-step observer used as receiver. The transmitter parameters play the role of secret keys of the transmission scheme. To increase the robustness of the secure data transmission against known plain-text attacks, the message to be sent is encrypted by additional secret keys and inserted by inclusion method in the chaotic discrete-time system dynamics. By this way, the parameters used as secret keys cannot be identified with usual techniques. Simulation results are presented to highlight the performances of the proposed method. One of the main contributions of this paper is to demonstrate the feasibility of discrete realization of a chaotic observer-based secured transmission scheme. Indeed, experimental implementation results using Arduino Uno board validate the proposed approach, since it exhibits good performances of throughput and cost in terms of resources used.

Description: This paper is concerned with the problem of complex function projective synchronization for uncertain networked chaotic complex systems. Based on Lyapunov stability, an adaptive control method is proposed for complex modified projective synchronization, which guarantees that the general drive-response networked chaotic complex systems are synchronized up to a complex scaling function matrix. Moreover, a complex fuzzy logic-based observer is designed to compensate for the model uncertainties and the external disturbances that exist in response networks, without prior information about uncertain factors. Numerical simulations are presented to demonstrate the effectiveness of the proposed method.

Description: We investigate the spatiotemporal behaviour of a network where the local dynamics at the nodes (sites) is governed by piecewise linear maps. The local maps we consider exhibit the interesting and potentially useful property of robust chaos. We study the coupled system of such maps with varying fraction of random non-local connections, where the random links may be static, or may change over time. While this system is always unsynchronized under regular connections, synchronized chaos emerges when some of the links are rewired randomly. Further, increasing the frequency of link changes and fraction of random links significantly enhances the range of synchronization. Additionally, dynamic random links are also found to suppress unbounded dynamics in parameter regimes where blow-ups occurred under regular coupling.

Description: Chaotic delay systems are abundant in nature and play a significant role in engineering applications and in describing global behaviors of physical systems. This work presents novel first-order chaotic delay systems with the simplest nonlinearities. The exponential, absolute value, and hyperbolic and signum functions, which arise in many systems like electronic circuits, are utilized to generate chaotic delay systems. The practical realization of chaotic delay systems is carried out with all-pass filters and diode-based electronic circuits. Bifurcation diagrams using numerical simulations and experimental results are provided to verify the existence and feasibility of the novel chaotic delay systems. It is expected that the novel chaotic delay systems and the novel electronic implementation circuits will contribute to some practical applications and modeling of physical systems or events in different fields.

Description: Based on the state-dependent Riccati equation (SDRE) technique, in this paper, a suboptimal pinning control scheme is proposed to synchronize linearly coupled complex networks. The Lyapunov direct method is used to analyze the stability of the closed-loop control system, where it leads to a LMI criterion for pinning synchronization. It is shown that the time interval for synchronization of the proposed SDRE controllers is faster comparing with the results in the latest literatures. It is also shown that the minimum required coupling weights for the network synchronization in a finite desired time is decreased when some specified nodes in the network are pinned with the SDRE controllers. Based on the proposed criterion for pinned nodes selection, the network performances for different topological structures are investigated and the results are compared. The results indicate that the coupling weights for network synchronization in finite desired time in random Erdos Reiny networks are minimum when the pinned nodes are selected based on the minimum matching theorem. In small-world and scale-free networks, the minimum required coupling weight for network synchronization in finite desired time decreases when the highest degree nodes are pinned.

Description: In recent years, digital image processing has become commonplace with growing powerful and available image editing software. People without any professional technique can also manipulate and forge digital images easily. One of the most popular manners of digital image forgeries is the copy–move image forgery. Extensive researches in detecting copy–move forgery have made a deal of achievements, but most presented methods based on these researches have been only focus on some simple composite forgeries and not able to detect different types of post-processed forgeries. In this paper, we aim to deal with the post-processed forgery operations and scenarios, mainly geometric distortion. We introduce analytical Fourier–Mellin transform (AFMT) and focus on its discretization. We propose discrete analytical Fourier–Mellin transform (DAFMT). We also pay attention to high performance of DAFMT in detecting the copy–move image forgeries. Due to the AFMT described in polar coordinate, so we need to convert coordinate system from polar to Cartesian coordinates. To be computed conveniently, we define an auxiliary disk template to accomplish this conversion. We devote to the use of our proposed DAFMT in detection of image forgeries. A great deal of researches and experiments show that the proposed DAFMT can effectively resist translation, rotation, scaling, and added Gaussian noise operations. Compared with other relevant up-to-date methods, experiments also prove that DAFMT has made a progress in detecting and identifying the forgery images which are suffered from geometric distortion operations.

Description: The production of the massive bosons \(Z^0\) and \(W^{\pm }\) could provide an excellent tool to study cold nuclear matter effects and the modifications of nuclear parton distribution functions (nPDFs) relative to the parton distribution functions (PDFs) of a free proton in high-energy nuclear reactions at the LHC as well as in heavy-ion collisions (HIC) with much higher center-of-mass energies available in the future colliders. In this paper we calculate the rapidity and transverse momentum distributions of the vector boson and their nuclear modification factors in p + Pb collisions at \(\sqrt{s_{NN}}=63\)  TeV and in Pb + Pb collisions at \(\sqrt{s_{NN}}=39\)  TeV in the framework of perturbative QCD by utilizing three parametrization sets of nPDFs: EPS09, DSSZ, and nCTEQ. It is found that in heavy-ion collisions at such high colliding energies, both the rapidity distribution and the transverse momentum spectrum of vector bosons are considerably suppressed in wide kinematic regions with respect to p + p reactions due to large nuclear shadowing effect. We demonstrate that the massive vector boson production processes with sea quarks in the initial state may give more contributions than those with valence quarks in the initial state; therefore in future heavy-ion collisions the isospin effect is less pronounced and the charge asymmetry of the W boson will be reduced significantly as compared to that at the LHC. A large difference between results with nCTEQ and results with EPS09 and DSSZ is observed in nuclear modifications of both rapidity and \(p_T\) distributions of \(Z^0\) and W in the future HIC.

Description: We present a frequentist analysis of the parameter space of the pMSSM10, in which the following ten soft SUSY-breaking parameters are specified independently at the mean scalar top mass scale \(M_\mathrm{SUSY}\equiv \sqrt{m_{\tilde{t}_{1}} m_{\tilde{t}_{2}}}\) : the gaugino masses \(M_{1,2,3}\) , the first-and second-generation squark masses \(m_{\tilde{q}_1}= m_{\tilde{q}_2}\) , the third-generation squark mass \(m_{\tilde{q}_3}\) , a common slepton mass \(m_{\tilde{\ell }}\) and a common trilinear mixing parameter A , as well as the Higgs mixing parameter \(\mu \) , the pseudoscalar Higgs mass \(M_A\) and \(\tan \beta \) , the ratio of the two Higgs vacuum expectation values. We use the MultiNest sampling algorithm with \(\sim \) 1.2 \(\times 10^9\) points to sample the pMSSM10 parameter space. A dedicated study shows that the sensitivities to strongly interacting sparticle masses of ATLAS and CMS searches for jets, leptons \(+\) signals depend only weakly on many of the other pMSSM10 parameters. With the aid of the Atom and Scorpion codes, we also implement the LHC searches for electroweakly interacting sparticles and light stops, so as to confront the pMSSM10 parameter space with all relevant SUSY searches. In addition, our analysis includes Higgs mass and rate measurements using the HiggsSignals code, SUSY Higgs exclusion bounds, the measurements of \(\mathrm{BR}(B_s \rightarrow \mu ^+\mu ^-)\) by LHCb and CMS, other B -physics observables, electroweak precision observables, the cold dark matter density and the XENON100 and LUX searches for spin-independent dark matter scattering, assuming that the cold dark matter is mainly provided by the lightest neutralino \(\tilde{\chi }^0_{1}\) . We show that the pMSSM10 is able to provide a supersymmetric interpretation of \((g-2)_\mu \) , unlike the CMSSM, NUHM1 and NUHM2. As a result, we find (omitting Higgs rates) that the minimum \(\chi ^2 = 20.5\) with 18 degrees of freedom (d.o.f.) in the pMSSM10, corresponding to a \(\chi ^2\) probability of 30.8 %, to be compared with \(\chi ^2/\mathrm{d.o.f.} = 32.8/24 \ (31.1/23) \ (30.3/22)\) in the CMSSM (NUHM1) (NUHM2). We display the one-dimensional likelihood functions for sparticle masses, and we show that they may be significantly lighter in the pMSSM10 than in the other models, e.g., the gluino may be as light as \(\sim \) 1250 \(\,\, \mathrm {GeV}\) at the 68 % CL, and squarks, stops, electroweak gauginos and sleptons may be much lighter than in the CMSSM, NUHM1 and NUHM2. We discuss the discovery potential of future LHC runs, \(e^+e^-\) colliders and direct detection experiments.

Description: We compute the corrections to the Schwarzschild metric necessary to reproduce the Hawking temperature derived from a generalized uncertainty principle (GUP), so that the GUP deformation parameter is directly linked to the deformation of the metric. Using this modified Schwarzschild metric, we compute corrections to the standard general relativistic predictions for the light deflection and perihelion precession, both for planets in the solar system and for binary pulsars. This analysis allows us to set bounds for the GUP deformation parameter from well-known astronomical measurements.

Description: LHC searches for non-standard Higgs bosons decaying into tau lepton pairs constitute a sensitive experimental probe for physics beyond the Standard Model (BSM), such as supersymmetry (SUSY). Recently, the limits obtained from these searches have been presented by the CMS collaboration in a nearly model-independent fashion – as a narrow resonance model – based on the full \(8\,\, \mathrm {TeV}\) dataset. In addition to publishing a \(95~\%~\mathrm {C.L.}\) exclusion limit, the full likelihood information for the narrow resonance model has been released. This provides valuable information that can be incorporated into global BSM fits. We present a simple algorithm that maps an arbitrary model with multiple neutral Higgs bosons onto the narrow resonance model and derives the corresponding value for the exclusion likelihood from the CMS search. This procedure has been implemented into the public computer code HiggsBounds (version 4.2.0 and higher). We validate our implementation by cross-checking against the official CMS exclusion contours in three Higgs benchmark scenarios in the Minimal Supersymmetric Standard Model (MSSM), and find very good agreement. Going beyond validation, we discuss the combined constraints of the \(\tau \tau \) search and the rate measurements of the SM-like Higgs at \(125\,\, \mathrm {GeV}\) in a recently proposed MSSM benchmark scenario, where the lightest Higgs boson obtains SM-like couplings independently of the decoupling of the heavier Higgs states. Technical details for how to access the likelihood information within HiggsBounds are given in the appendix. The program is available at http://higgsbounds.hepforge.org .

Description: The problem of controlling synchrony in bistable networks, which possess coherent and incoherent attractors in a certain range of parameters, is considered. Along with the known Kuramoto-type models, we introduce the bistable networks consisting of all-to-all coupled noisy FitzHugh-Nagumo neurons as well as chaotic Rulkov neurons. We suggest two different algorithms to switch the bistable networks from the stable coherent state to the stable incoherent state. One of them is an act-and-wait control method, which utilizes the mean field measurements and homogeneous time delayed feedback perturbations with the periodically switched on and off feedback gain. We show that this algorithm is efficient for the globally coupled populations. Another algorithm is based on the multisite coordinated reset stimulation. The algorithm is nonfeedback, but it uses inhomogeneous perturbations and is efficient even for the networks with a complex scale-free topology. In addition to the numerical analysis of finite-size networks, the analytical results for the Kuramoto-type models in the thermodynamic limit are presented.

Description: Considering topography conditions, economic factors and driving safety, in real traffic, a road may be built as curved road. Traffic flow on curved road is different from the one on straight road. And it is worth to investigate the influencing mechanism of traffic flow on curved road. In order to investigate traffic flow on curved road analytically, in this paper, an extended one-dimensional lattice hydrodynamic model for traffic flow on curved road is proposed. The stability condition is obtained by the use of linear stability analysis. It is shown that the stability of traffic flow varies with the radian, friction coefficient and curvature radius of curved road. The Burgers, Korteweg–de Vries and modified Korteweg–de Vries equations are derived to describe the nonlinear density waves in the stable, metastable and unstable regions, respectively. The simulations are given to verify the analytical results. The results, which obtained from the theoretical analysis and numerical simulations, show that traffic flow may be affected by the angle going into curved road, the increment of angle, friction coefficient and curvature radius of curved road. And the maximal theoretical flux and velocity of traffic flow are influenced by the above factors as well.

Description: This paper focuses on the adaptive modified hybrid function projective synchronization with complex function transformation matrix (CMHFPS) for different dimensional chaotic (hyperchaotic) systems with complex variables and unknown complex parameters. The chaotic systems are considerably different from those in the existing closely related literature. Moreover, the transformation matrix in this type of chaos synchronization is not a square matrix, and its elements are complex functions. In particular, by constructing appropriate Lyapunov functions dependent on complex variables, the adaptive controllers are designed to synchronize different dimensional complex chaos (hyperchaos) with complex parameters in the sense of CMHFPS, and the complex update laws for estimating unknown complex parameters of complex chaotic systems are also given. Finally, two examples are presented to illustrate the effectiveness and feasibility of the theoretical results.

Description: In this paper, an experimental verification of the vibro-impact capsule model proposed by Liu et al. in (Int. J. Mech. Sci, 66:2–11; 2013a , Int. J. Mech. Sci, 72:39–54; 2013b , Int. J. Non-Linear Mech., 70, 30–46; 2015 ) is presented. The capsule dynamics is investigated experimentally by varying the stiffness of the support spring, and the frequency and the amplitude of excitation. The novel design of the experimental set-up is discussed, and comparisons between the experiments and numerical simulations are presented showing a good agreement. The conducted bifurcation analysis indicates that the behaviour of the system is mainly periodic and that a fine tuning of the control parameters can significantly improve the performance of the system. The main findings provide a better insight into the vibro-impact systems subject to nonlinear friction, and the experimental rig can be used to predict the dynamic behaviour of these systems.

Description: Based on the stability theory of fractional-order systems, using the fractional-order Lyapunov direct method, in this paper, the Mittag–Leffler stability for fractional-order Lorenz and fractional-order Lorenz-family system is investigated, respectively. We propose the definition of the Mittag–Leffler stability; some sufficient conditions for the Mittag–Leffler stability are obtained by selecting properly the parameters and the initial values of system. Finally, numerical simulations are performed to verify the theoretical analysis.

Description: In this paper, cluster synchronization on multiple sub-networks of complex networks with nonidentical nodes, stochastic disturbances and time-varying delays is investigated. Based on the leader–follower model, an improved network structure model for realizing the cluster synchronization on multiple sub-networks of complex networks is presented. In this improved network model, the complex networks are divided into multiple pairs of matching sub-networks, each of which consists of a leaders’ sub-network and a followers’ sub-network, such that the dynamics of the nodes belonging to the same pair of matching sub-networks are identical, while the ones belonging to different pairs of unmatched sub-networks are nonidentical. Furthermore, the nodes in a sub-network may be inevitably influenced by some stochastic disturbances and time-varying delays. In this new setting, the aim is to design some suitable pinning controllers on the chosen nodes of each followers’ sub-network, such that the proposed method for realizing the cluster synchronization has good immunity to the influence of these stochastic factors. By using the Lyapunov stability theory and stochastic differential equation theory, some cluster synchronization criteria, and a pinning scheme that the nodes with very large or low degrees are good candidates for applying pinning controllers, are established such that all the nodes in each sub-network are exponentially synchronized to the average state of their matching leaders. Then, the attack and robustness of the pinning scheme are discussed. Finally, some simulation examples are presented to verify the theoretical analysis.

Description: This paper introduces a new segmentation technique to segment incomplete nutrient-deficient crop images by imputing missing pixels. Usually, each image contains pixels holding information about intensity, but sometimes image can miss some pixels (that is, the pixel without an appropriate intensity value). An image with missing pixels is called an incomplete image. Intuitionistic fuzzy clustering algorithm is a useful tool for clustering images, but it is not directly applicable for incomplete images. For example, segmentation of nutrient deficiency portions in the presence of missing pixels leads to error in segmentation. Crop images with nutrient deficiency might have missing pixels due to inherent defects in imaging equipment or due to environmental conditions. In this paper, nutrient deficiency in crop images is segmented after imputation of missing pixels based on intuitionistic fuzzy C-means color clustering algorithm. Experiments are performed on various incomplete crop images. Through the derived results and evaluated comparisons with other methods, namely K-means, fuzzy K-means, principal component analysis, regularized expectation maximization and fuzzy C-means algorithms, it has been proven that the proposed method performs well.

Description: Theoretical analysis of a suspended nano-mechanical membrane subject to an optical driving field in an optomechanical cavity is presented, which is confirmed through numerical simulations. In the presence of an optical field between its mirrors, the high-finesse optomechanical resonator acts as an oscillator driven by a radiation pressure force. The periodic nature of the radiation pressure force makes the nano-mechanical membrane in the optomechanical system as a kicked harmonic oscillator. Mathematically the physical system displays a stochastic web map that helps to understand several properties of the kicked membrane in classical phase space. We find that our web map is area preserving and displays quasiperiodic symmetrical structures in phase space which we express as q -fold symmetry. It is shown that under appropriate control of certain parameters, namely the frequency ratio and the kicking strength, the dynamics of kicked membrane exhibits chaotic dynamics. We provide the stability analysis by means of Lyapunov exponent and survival probability.

Description: We study the coupled nonlinear Schrödinger equation in the (2+1)-dimensional inhomogeneous \(\mathcal {PT}\) -symmetric nonlinear couplers and obtain \(\mathcal {PT}\) -symmetric and \(\mathcal {PT}\) -antisymmetric vortex soliton solutions. The dynamical behaviors of the completely localized structures (vortex solitons) are analytically and numerically investigated in a diffraction decreasing system with exponential profile. Numerical results indicate that one vortex soliton with different topological charges can stably propagate a long distance. The space between two humps and the modulation depth of vortex solitons add when the topological charge increases. However, the change tendency of the amplitude and width of vortex solitons is same with the increase in topological charge.

Description: We investigate inflation within \(f(R,\phi )\) -theories, where a dynamical scalar field is coupled to gravity. A class of models which can support early-time acceleration with the emerging of an effective cosmological constant at high curvature is studied. The dynamics of the field allow for exit from inflation leading to the correct amount of inflation in agreement with cosmological data. Furthermore, the spectral index and tensor-to-scalar ratio of the models are carefully analyzed. A generalization of the theory to incorporate dark matter in the context of mimetic gravity, and further extensions of the latter, are also discussed.

Description: The existence of both a minimum mass and a minimum density in nature, in the presence of a positive cosmological constant, is one of the most intriguing results in classical general relativity. These results follow rigorously from the Buchdahl inequalities in four-dimensional de Sitter space. In this work, we obtain the generalized Buchdahl inequalities in arbitrary space–time dimensions with \(\Lambda \ne 0\) and consider both the de Sitter and the anti-de Sitter cases. The dependence on D , the number of space–time dimensions, of the minimum and maximum masses for stable spherical objects is explicitly obtained. The analysis is then extended to the case of dark energy satisfying an arbitrary linear barotropic equation of state. The Jeans instability of barotropic dark energy is also investigated, for arbitrary D , in the framework of a simple Newtonian model with and without viscous dissipation, and we determine the dispersion relation describing the dark energy–matter condensation process, along with estimates of the corresponding Jeans mass (and radius). Finally, the quantum mechanical implications of the mass limits are investigated, and we show that the existence of a minimum mass scale naturally leads to a model in which dark energy is composed of a ‘sea’ of quantum particles, each with an effective mass proportional to \(\Lambda ^{1/4}\) .

Description: We study multi-soliton solutions of the four-dimensional SU(N) Skyrme model by combining the hedgehog ansatz for SU(N) based on the harmonic maps of \(S^{2}\) into \(CP^{N-1}\) and a geometrical trick which allows to analyze explicitly finite-volume effects without breaking the relevant symmetries of the ansatz. The geometric set-up allows to introduce a parameter which is related to the ’t Hooft coupling of a suitable large N limit, in which \(N\rightarrow \infty \) and the curvature of the background metric approaches zero, in such a way that their product is constant. The relevance of such a parameter to the physics of the system is pointed out. In particular, we discuss how the discrete symmetries of the configurations depend on it.

Description: The effects of color reconnection (CR) at \({\mathrm e}^+{\mathrm e}^-\) colliders are revisited, with focus on recently developed CR models. The new models are compared with the LEP2 measurements for \({\mathrm e}^+{\mathrm e}^- \rightarrow {\mathrm W}^+{\mathrm W}^- \rightarrow {\mathrm q}_1 \overline{\mathrm q}_2 {\mathrm q}_3 \overline{\mathrm q}_4\) and found to lie within their limits. Prospects for constraints from new high-luminosity \({\mathrm e}^+{\mathrm e}^-\) colliders are discussed. The novel arena of CR in Higgs decays is introduced, and it is illustrated by shifts in angular correlations that would be used to set limits on a potential CP -odd admixture of the 125 GeV Higgs state.

Description: The detection of shaft cracks within operating rotors is an old subject of scientific research. Several signal- and model-based approaches are developed. Here two approaches used for crack detection in rotating machinery, model-based and signal-based approaches, are compared. Strength and weak points are discussed and compared for the two approaches using two representative applicable methods, in order to achieve a comparative overview of these two available techniques. The PI-observer-based method is considered, as modern model-based technique, to give indication about possibilities and limitations of such kind of methods. A novel signal-based approach is introduced, based on SVM and wavelets as an example for a modern machine learning technique. The concepts of severity estimation and service life prediction are investigated in the proposed approach. Furthermore, a brief comparative discussion is presented in the contribution, including ideas for combination of the introduced approaches, in order to achieve more comprehensive and more robust monitoring system applied to the detection of shaft cracks in rotating machines.

Description: The Lorentz transformation properties of the equal-time bound-state Bethe–Salpeter amplitude in the two-dimensional massless quantum electrodynamics (the so-called Schwinger model) are considered. It is shown that while boosting a bound state (a ‘meson’) this amplitude is subject to approximate Lorentz contraction. The effect is exact for large separations of constituent particles (‘quarks’), while for small distances the deviation is more significant. For this phenomenon to appear, the full function, i.e. with the inclusion of all instanton contributions, has to be considered. The amplitude in each separate topological sector does not exhibit such properties.

Description: The canonical Aharonov–Bohm effect is usually studied with time-independent potentials. In this work, we investigate the Aharonov–Bohm phase acquired by a charged particle moving in time-dependent potentials. In particular, we focus on the case of a charged particle moving in the time-varying field of a plane electromagnetic wave. We work out the Aharonov–Bohm phase using both the potential (i.e. \(\oint A_\mu \mathrm{d}x ^\mu \) ) and the field (i.e. \(\frac{1}{2}\int F_{\mu \nu } \mathrm{d}\sigma ^{\mu \nu }\) ) forms of the Aharonov–Bohm phase. We give conditions in terms of the parameters of the system (frequency of the electromagnetic wave, the size of the space–time loop, amplitude of the electromagnetic wave) under which the time-varying Aharonov–Bohm effect could be observed.

Description: The LHC data on jet fragmentation function and jet shapes in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the frameworks of PYthia QUENched (PYQUEN) jet quenching model. A specific modification of longitudinal and radial jet profiles in most central PbPb collisions as compared with pp data is close to that obtained with PYQUEN simulations, taking into account wide-angle radiative and collisional partonic energy losses. The contribution of radiative and collisional loss to the medium-modified intra-jet structure is estimated.

Description: When averages of different experimental determinations of the same quantity are computed, each with statistical and systematic error components, then frequently the statistical and systematic components of the combined error are quoted explicitly. These are important pieces of information since statistical errors scale differently and often more favorably with the sample size than most systematical or theoretical errors. In this communication we describe a transparent procedure by which the statistical and systematic error components of the combination uncertainty can be obtained. We develop a general method and derive a general formula for the case of Gaussian errors with or without correlations. The method can easily be applied to other error distributions, as well. For the case of two measurements, we also define disparity and misalignment angles, and discuss their relation to the combination weight factors.