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
    Analysis of the Thomas-Fermi-von Weizsäcker equation for an infinite atom without electron repulsion (1982)
    Springer
    Communications in mathematical physics 85 (1982), S. 15-25 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract The equation $$\left\{ { - \Delta + |\psi (x)|^{2p - 2} - |x|^{ - 1} } \right\}\psi (x) = 0$$ in three dimensions is investigated. Uniqueness and other properties of the positive solution are proved for 3/2〈p〈2. There are two physical interpretations of this equation forp=5/3: (i) As the TFW equation for an infinite atomwithout electron repulsion; (ii) The positive solution, ψ, suitably scaled, is asymptotically equal to the solution of the TFW equation for an atom or moleculewith electron repulsion in the regime where the nuclear charges are large andx is close to one of the nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02029130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The inverse problem in classical statistical mechanics (1984)
    Springer
    Communications in mathematical physics 93 (1984), S. 57-121 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract We address the problem of whether there exists an external potential corresponding to a given equilibrium single particle density of a classical system. Results are established for both the canonical and grand canonical distributions. It is shown that for essentially all systems without hard core interactions, there is a unique external potential which produces any given density. The external potential is shown to be a continuous function of the density and, in certain cases, it is shown to be differentiable. As a consequence of the differentiability of the inverse map (which is established without reference to the hard core structure in the grand canonical ensemble), we prove the existence of the Ornstein-Zernike direct correlation function. A set of necessary, but not sufficient conditions for the solution of the inverse problem in systems with hard core interactions is derived.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01218639
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Minimum action solutions of some vector field equations (1984)
    Springer
    Communications in mathematical physics 96 (1984), S. 97-113 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract The system of equations studied in this paper is −Δu i =g i (u) on ℝ d ,d≧2, withu:ℝ d →ℝ n andg i (u)=∂G/∂u i . Associated with this system is the action,S(u)=ε{1/2|∇u|2−G(u)}. Under appropriate conditions onG (which differ ford=2 andd≧3) it is proved that the system has a solution,u ≢0, of finite action and that this solution also minimizes the action within the class {v is a solution,v has finite action,v ≢0}.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01217349
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    One-electron relativistic molecules with Coulomb interaction (1983)
    Springer
    Communications in mathematical physics 90 (1983), S. 497-510 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract As an approximation to a relativistic one-electron molecule, we study the operator $$H = ( - \Delta + m^2 )^{1/2} - e^2 \sum\limits_{j = 1}^K {Z_j } |x - R_j |^{ - 1}$$ withZ j ≧0,e −2=137.04.H is bounded below if and only ife 2 Z j ≦2/π allj. Assuming this condition, the system is unstable whene 2∑Z j 〉2/π in the sense thatE 0=inf spec(H)→−∞ as the R j →0, allj. We prove that the nuclear Coulomb repulsion more than restores stability; namely $$E_0 + 0.069e^2 \sum\limits_{i〈 j} {Z_i Z_j } |R_i - R_j |^{ - 1} \geqq 0$$ . We also show thatE 0 is an increasing function of the internuclear distances |R i −R j |.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01216181
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    On characteristic exponents in turbulence (1984)
    Springer
    Communications in mathematical physics 92 (1984), S. 473-480 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract Ruelle has found upper bounds to the magnitude and to the number of non-negative characteristic exponents for the Navier-Stokes flow of an incompressible fluid in a domain Θ. The latter is particularly important because it yields an upper bound to the Hausdorff dimension of attracting sets. However, Ruelle's bound on the number has three deficiences: (i) it relies on some unproved conjectures about certain constants; (ii) it is valid only in dimensions ≧ 3 and not 2; (iii) it is valid only in the limit Θ → ∞. In this paper these deficiences are remedied and, in addition, the final constants in the inequality are improved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01215277
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Integral bounds for radar ambiguity functions and Wigner distributions (1990)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 31 (1990), S. 594-599 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: An upper bound is proved for the Lp norm of Woodward's ambiguity function in radar signal analysis and of the Wigner distribution in quantum mechanics when p〉2. A lower bound is proved for 1≤p〈2. In addition, a lower bound is proved for the entropy. These bounds set limits to the sharpness of the peaking of the ambiguity function or Wigner distribution. The bounds are best possible and equality is achieved in the Lp bounds if and only if the functions f and g that enter the definition are both Gaussians.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.528894
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Uniform density theorem for the Hubbard model (1993)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 34 (1993), S. 891-898 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: A general class of hopping models on a finite bipartite lattice is considered, including the Hubbard model and the Falicov–Kimball model. For the half-filled band, the single-particle density matrix ρ(x,y) in the ground state and in the canonical and grand canonical ensembles is shown to be constant on the diagonal x=y, and to vanish if x≠y and if x and y are on the same sublattice. For free electron hopping models, it is shown in addition that there are no correlations between sites of the same sublattice in any higher order density matrix. Physical implications are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.530199
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    VIOLATION OF THE NONCROSSING RULE: THE HUBBARD HAMILTONIAN FOR BENZENE (1971)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 172 (1971), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Notes: The Hubbard Hamiltonian, while not one of the most successful models for π electrons in benzene, has been extensively investigated in the literature. As part of our general study of that model, we have computed all the energy levels for all values of the repulsion parameter—a task that has not been undertaken before. After extracting all the symmetry of the model we found, to our great surprise, many instances of permanent degeneracy of levels with different symmetry and also crossing of levels of the same symmetry. We can also demonstrate that there is no hidden symmetry to account for these effects. Since these results run counter to one of the oldest folk theorems in quantum chemistry, our otherwise uninspiring graphs may be of general interest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1971.tb34956.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Valence bond ground states in isotropic quantum antiferromagnets (1988)
    Springer
    Communications in mathematical physics 115 (1988), S. 477-528 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract Haldane predicted that the isotropic quantum Heisenberg spin chain is in a “massive” phase if the spin is integral. The first rigorous example of an isotropic model in such a phase is presented. The Hamiltonian has an exactSO(3) symmetry and is translationally invariant, but we prove the model has a unique ground state, a gap in the spectrum of the Hamiltonian immediately above the ground state and exponential decay of the correlation functions in the ground state. Models in two and higher dimension which are expected to have the same properties are also presented. For these models we construct an exact ground state, and for some of them we prove that the two-point function decays exponentially in this ground state. In all these models exact ground states are constructed by using valence bonds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01218021
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Approximate neutrality of large-Z ions (1988)
    Springer
    Communications in mathematical physics 116 (1988), S. 635-644 
    Details
    ISSN: 1432-0916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract LetN(Z) denote the number of electrons which a nucleus of chargeZ can bind in non-relativistic quantum mechanics (assuming that electrons are fermions). We prove thatN(Z)/Z→1 asZ→∞.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01224904
    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...