ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Limiting Gibbs states and dynamics for thermal photons (1992)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 33 (1992), S. 143-151 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: For thermal photons, the limiting Gibbs state is investigated in the framework of algebraic quantum theory. For the one-particle Hamiltonian, the square root of the local Laplacians with Dirichlet boundary conditions is used. The local regions are only demanded to have the segment property and the thermodynamic limit is performed along a nearly arbitrary family of such local regions. Also, the limiting dynamics as a noncontinuous group of Bogoliubov transformations on an extension of the quasilocal Weyl algebra and as a W* dynamics on the GNS–von Neumann algebra is derived. After having performed the limits, the photon algebra is restricted to the physical (transversal) photons. The crucial mathematical method in verifying these results are comparisons of the semigroups of the square root of the Laplacians in different regions of the ν-dimensional Euclidean space by means of the ordering of positivity preserving operators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.529953
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Rigorous derivation of Planck's law in the thermodynamic limit (1992)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 33 (1992), S. 343-348 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: The limiting Gibbs state and dynamics for free thermal photons was investigated in a previous work by means of an operator algebraic approach. For the one-photon Hamiltonian in a local region, the square root of the Laplacian with Dirichlet boundary conditions was used. In the present work, the energy density distribution for thermal photons (Planck's law) in a nearly arbitrary physical cavity is derived in the thermodynamic limit. For the cavity, only the segment property and a zero-set boundary is assumed, which is the weakest possible requirement at its border. For the thermodynamic limit, the cavity is monotonously dilated from a fixed interior point. In this sense, the work is also a contribution to Weyl's problem, the asymptotic distribution of the eigenvalues of the wave equation in the infinite space approximation. The calculation uses comparisons of functions of the Laplacians defined in different regions of the Euclidean space by means of the ordering of positivity preserving operators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.529912
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Enlarged test-function spaces for the global free folia dynamics on the CCR-algebra (1998)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 39 (1998), S. 1153-1169 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: The global free dynamics for the boson field is investigated for the test-function space D(R3) of infinitely differentiable functions with compact support in the position space R3. D(R3) is not invariant with respect to the one-boson dynamics, and thus the free dynamics cannot be formulated in terms of Bogoliubov automorphisms on the CCR-algebra over D(R3). In the Schrödinger picture the free dynamics here is constructed in terms of a group of affine bijections on suitable folia of the CCR-algebra so that the expectations are continuous in time. These folia contain a continuum of disjoint subfolia, namely the squeezed vacuum sectors. Those squeezed vacuum sectors are determined which give rise to covariant dynamical subdescriptions, that is, for which the time evolution of the states satisfies the stronger time-continuity with respect to the norm, and thus in the Heisenberg picture lead to W*-dynamical systems. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.532377
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Unitary implementations of one-parameter squeezing groups (1998)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 39 (1998), S. 777-801 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: For the case of infinitely many photon (Boson) modes we investigate the unitary implementability of a class of symplectic one-parameter groups (more exactly, of the associated groups of Bogoliubov automorphisms on the CCR algebra) in the Fock representation and in representations of the CCR algebra, which are symplectically related and inequivalent to Fock. Furthermore, the existence of the associated (squeezing) quadratic Hamiltonians is discussed. Finally, applications in the theory of quantization in QED and in the Luttinger model are pointed out. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.532352
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Squeezing Bogoliubov transformations on the infinite mode CCR-algebra (1996)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 37 (1996), S. 4292-4309 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: A detailed analysis of and a general decomposition theorem for in general unbounded symplectic transformations on an arbitrary complex pre-Hilbert space (one–boson test function space) are given. The structure of strongly continuous symplectic groups on such spaces is determined. The connection between quadratic Hamiltonians, Bogoliubov transformations, and symplectic transformations is discussed in the Fock representation, and their relevance for squeezing operations in quantum optics is pointed out. The results for this rather general class of transformations are proved in a self-contained fashion. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.531656
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Limiting dynamics of generalized Bardeen–Cooper–Schrieffer models beyond the pair algebra (1993)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 34 (1993), S. 943-968 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: Bardeen–Cooper–Schrieffer (BCS)-like models for permutation invariant electronic interactions are investigated in terms of recent rigorous mean-field methods. Their limiting dynamics is constructed in the Heisenberg picture on (extensions of) the full canonical commutation relation (CAR) algebra and also restricted to (extensions of) the pair algebra. The classical part of the proper BCS dynamics on the CAR algebra is shown to exhibit 15 macroscopic collective variables, the time dependence of which is explicitly integrated and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.530203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Global cocycle dynamics for infinite mean field quantum systems interacting with the boson gas (1996)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 37 (1996), S. 263-282 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: In the framework of operator algebraic quantum statistical mechanics, the global nonequilibrium dynamics for a general class of interactions of infinite mean field quantum lattice systems with the boson field is investigated. The associated interaction operators consist of arbitrary powers of the collective density operators of the mean field system and are linear with respect to the bosonic field operators. Instead of the usual perturbation expansions, here the interacting dynamics are studied by means of cocycle techniques. The cocycle methods are more appropriate to the considered class of interactions, and lead to explicit closed expressions for the dynamical automorphism groups. The cocycle equations connect the classical, collective dynamical behavior of the mean field system with the one-boson dynamics. In physical applications such systems are due to collectively ordered finite-level atoms or the Josephson junction in the thermodynamic limit weakly interacting with the electromagnetic field. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.531390
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    The extremal microscopic coherent boson states (1993)
    Springer
    Letters in mathematical physics 28 (1993), S. 155-164 
    Details
    ISSN: 1573-0530
    Keywords: 81V80 ; 47D45 ; 46N55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract In a recent paper, the Fock-normal (=microscopic) fully-coherent statesL L (∞) (L denotes the factorizing linear form) have been completely characterized, and the existence of nonpure elements in the extreme boundary of the weak-*-compact, convex setL L has been shown. This letter is devoted to an analysis of the extremal fully-coherent states, especially those which are not pure states. An affine isomorphism is constructed betweenL L (∞) and a certain convex subset of the normal completely positive maps on the bounded operators on Fock space. Then the extreme boundary ofL L (∞) is determined by results and techniques from the theory of completely positive operators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    On higher-order coherent states of the Weyl algebra (1992)
    Springer
    Letters in mathematical physics 24 (1992), S. 221-225 
    Details
    ISSN: 1573-0530
    Keywords: 81V80 ; 47D45 ; 46N55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract It is shown that for classical, analytical states of the Weyl algebra, the quantum optical coherence condition of second order implies those of nth order for all n≥2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402897
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    On the dynamics and the temperature states of the spin-boson model (1991)
    Springer
    Letters in mathematical physics 21 (1991), S. 351-359 
    Details
    ISSN: 1573-0530
    Keywords: 46L60 ; 82A15 ; 81G10 ; 81K05
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract Recently, the finite temperature states of the spin-boson model were studied. Here with different techniques in the case of level-splitting zero, the explicit expressions for both the dynamics and the equilibrium states are derived, namely Trotter's product formula and analyticity methods from perturbation theory are used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00398333
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...