共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Y. A. Gordon V. Jakšić S. Molčanov B. Simon 《Communications in Mathematical Physics》1993,157(1):23-50
We investigate spectral properties of random Schrödinger operators H = - + n()(1 + |n|) acting onl
2(Z
d), where n are independent random variables uniformly distributed on [0, 1].Research partially supported by a Sloan Doctoral Dissertation Fellowship and NSERC under grant OGP-0007901Research partially supported by NSF grant DMS-9101716 相似文献
3.
L. Raul W. Abramo 《International Journal of Theoretical Physics》2004,43(3):563-573
We investigate tachyon dynamics with an inverse power-law potential V ()
–. We find global attractors of the dynamics leading to a dust behavior for > 2 and to an accellerating universe for 0 < 2. We study linear cosmological perturbations and we show that metric fluctuations are constant on large scales in both cases. In the presence of an additional perfect fluid, the tachyon with this potential behaves as dust or dark energy. 相似文献
4.
J.G. Linhart 《Czechoslovak Journal of Physics》2003,53(9):791-797
-particles from fusion reactions in a DT magnetized plasma are confined inside the plasma not only by magnetic fields but also by induced electric fields which are due to the different mobilities of -particles and electrons. Criteria are derived for the -confinement in a cylindrical plasma, inertially confined by a heavy liner. It is observed that the suprathermal population in the DT plasma will influence the overall dynamics. 相似文献
5.
James L. Monroe 《Journal of statistical physics》1994,76(5-6):1505-1510
We present upper bounds on the critical temperature of one-dimensional Ising models with long-range,l/n
interactions, where 1<2. In particular for the often studied case of =2 we have an upper bound onT
c which is less than theT
c found by a number of approximation techniques. Also for the case where is small, such as =1.1, we obtain rigorous bounds which are extremely close, within 1.0%, to those found by approximation methods. 相似文献
6.
Ghosh Kamal Kumar Ray Dipankar Chanda Pranab 《International Journal of Theoretical Physics》1989,28(1):111-117
We present the complete set of solutions of the coupled differential equations of the form ()2=(), 2
=(). Equations of this form appear in several physical situations. 相似文献
7.
S. A. Goodman F. D. Auret G. Myburg 《Applied Physics A: Materials Science & Processing》1994,59(3):305-310
The annealing behaviour of irradiation induced defects in n-type GaAs irradiated at 300 K with 5.4 MeV alpha-particles from an americium-241 (Am-241) radio nuclide have been investigated. The annealing kinetics are presented for the alpha-particle induced defects E1–E5 detected in Organo-Metallic Vapor Phase Epitaxially (OMVPE) grown n-GaAs doped with silicon to 1.2×1016 cm–3, these kinetics are compared to those obtained for similar defects (E1–E5) detected after electron irradiation. While defects P1 and P2 were detected after removal of the electron defects E4 and E5, respectively, a new defect labelled P0, located 0.152 eV below the conduction band, was introduced by annealing. The thermal behaviour and trap characteristics of these three defects (P0–P2) are presented. In an attempt to further characterise defects P0 and P1 a preiliminary study investigating the emission rate field dependence of these defects was conducted, it was observed that defect P0 exhibited a fairly strong field dependence while P1 exhibited a much weaker dependence. 相似文献
8.
George Leibbrandt 《Letters in Mathematical Physics》1980,4(4):317-321
We derive in 3+0 dimensions exact solutions of Liouville's equation
2=exp , by applying the Bäcklund transformation technique in conjunction with the principle of nonlinear superposition. The procedure, which is later extended to 3+1 dimensions, yield, as a byproduct, particular solutions of
2
and
2
=exp (2
+2
). 相似文献
9.
Ola Bratteli Richard H. Herman Derek W. Robinson 《Communications in Mathematical Physics》1978,59(2):167-196
For automorphism groups of operator algebras we show how properties of the difference
t
– '
t
are reflected in relations between the generators , . Indeed for a von Neumann algebraM with separable predual we show that if t – 't 0.28 for smallt, then = 0(+)°-1 where is an inner automorphism ofM and is a bounded derivation ofM. If the difference
t
– '
t
=O(t) ast ; 0, then = + and if
t
– '
t
0.28 for allt then =. We prove analogous results for unitary groups on a Hilbert space andC
0,C
0
*
groups on a Banach space.This paper subsumes an earlier work of the same title which appeared as a report from Z.I.F. der Universität BielefeldWith partial support of the U.S. National Science Foundation 相似文献
10.
Let us consider a Lie (super)algebra G spanned by T where T are quantum observables in BV formalism. It is proved that for every tensor c... that determines a homology class of the Lie algebra G the expression c...T...T is again a quantum observable. This theorem is used to construct quantum observables in the BV sigma model. We apply this construction to explain Kontsevich's results about the relation between homology of the Lie algebra of Hamiltonian vector fields and topological invariants of manifolds. 相似文献
11.
The eigenvalues ofH()=H
0+H
*, whereH
* is an arbitrary Coulomb potential, decrease with increasing 0. Linear and parabolic bounds for the ground-state energy are presented. These bounds are applied to the biexciton and the exciton at a neutral donor. 相似文献
12.
We study the Sine-Gordon field theory at 2=8. We prove that the theory is renormalizable but not superrenormalizable and we show how the perturbative renormalization procedure works in this case where the interaction is not polynomial. To go beyond the perturbative results we investigate the -functional equation for this theory and discuss in what sense at 2=8 the theory is lacking the asymptotic freedom and how it is asymptotic free for 2<8 in a appropriate region of the coupling constants. 相似文献
13.
S. Albeverio G. Gallavotti R. Høegh-Krohn 《Communications in Mathematical Physics》1979,70(2):187-192
We show that for the regularized exponential interaction :e
: ind space-time dimensions the Schwinger functions converge to the Schwinger functions for the free field ifd>2 for all or ifd=2 for all such that ||>0.Partially sponsored by the I.H.E.S. through the Stiftung Volkswagenwerk 相似文献
14.
A. I. Bondarenko V. V. Rusakova D. A. Salomov G. M. Chernov 《Russian Physics Journal》1991,34(5):400-404
The transverse momentum spectra and correlation characteristics of secondary -particles (fragments of the24Mg nuclei) are studied. An excessive number of high-momentum -particles are found, which cannot be explained by the statistical model. It is shown that the azimuth correlations of -particles can be due to a large transverse momentum of the fragmenting residual magnesium nucleus.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 19–23, May, 1991. 相似文献
15.
G. Tauber 《General Relativity and Gravitation》1980,12(12):1043-1054
The spin-two particle is described by a symmetric tensorh
subject to the subsidiary conditionsh
=
h
=0. Their covariant generalization and the wave equation have been obtained directly from the Eulerian variational equations by algebraic methods only. In addition to the tensor fieldh
a symmetric third-rank tensor
=
as well as a vector fieldA
have been added, neither of which enter in the final result. The Lagrangian function is taken as a linear sum of all combinations which can be constructed from these functions, as well as terms involving the curvature tensor and its two possible contractions. Variation with respect toh
,
andA
independently gives the Euler equations. Combining the various trace equations and choice of arbitrary constants yields the subsidiary conditions, while the Euler equations themselves give the connection between the auxiliary functions and the tensorh
as well as the generalization of the wave equationD
D
h
+ 2R
h
-R
h
-R
h
+g
R
h
+Rh
=m
2
h
Finally, variation with respect tog
yields the energy-momentum tensor. 相似文献
16.
Successive band-splitting transitions occur in the one-dimensional map xi+1=g(xi),i=0, 1, 2,... withg(x)=x, (0 x 1/2) –x +, (1/2 <x 1) as the parameter is changed from 2 to 1. The transition point fromN (=2n) bands to 2Nbands is given by=(2)1/N (n=0, 1,2,...). The time-correlation function
i=xix0/(x0)2,xi xi–xi is studied in terms of the eigenvalues and eigenfunctions of the Frobenius-Perron operator of the map. It is shown that, near the transition point=2,
i–[(10–42)/17] i,0-[(102-8)/51]i,1 + [(7 + 42)/17](–1)ie–yi, where2(–2) is the damping constant and vanishes at=2, representing the critical slowing-down. This critical phenomenon is in strong contrast to the topologically invariant quantities, such as the Lyapunov exponent, which do not exhibit any anomaly at=2. The asymptotic expression for
i has been obtained by deriving an analytic form of
i for a sequence of which accumulates to 2 from the above. Near the transition point=(2)1/N, the damping constant of
i fori N is given by
N=2(N-2)/N. Numerical calculation is also carried out for arbitrary a and is shown to be consistent with the analytic results. 相似文献
17.
Yoel Tikochinsky 《International Journal of Theoretical Physics》1988,27(5):543-549
Starting with very simple assumptions, Feynman rules for the quantum mechanical amplitudes and the associated probabilities are derived. These rules emerge as the only consistent rules for manipulating complex amplitudes assigned to processes. The probability of a process to which an amplitudex has been assigned is determined asp(x)=|x|
, 0<2. If virtual processes are allowed,=2. 相似文献
18.
Shahen Hacyan 《General Relativity and Gravitation》1994,26(1):85-96
The Dirac spinors and matrices are used in combination with the Arnowitt-Deser-Misner formalism in order to obtain yet another formulation of Hamiltonian general relativity, together with a new form of the Gauss-Codazzi equations. The relation with Ashtekar's variables is analyzed; it is shown, for instance, that the matrices are equivalent to the electric field variable. The electric and magnetic decomposition of the gravitational field is also studie using Dirac matrices. 相似文献
19.
N. F. J. Matthews 《General Relativity and Gravitation》1992,24(1):17-33
The strength of Einstein's empty-space field equations is computed anew and shown to be equal to the amount of initial data required for a local solution of the equations. This same amount of initial data is shown to be precisely that required for a set of 16 unknown first-order differential equations containing 10 field variables and having six identities of second order. The 10 field variables must be functions of second order in the metric coefficients. The 16 field equationsC
, = 0 whereC
is Weyl's conformal tensor, are shown to have the same properties as those of the unknown equations, suggesting thatC
= 0 is a satisfactory local first-order formulation of Einstein's second-order empty-space field equations. 相似文献
20.
Ch. Zylka 《Journal of statistical physics》1990,60(1-2):281-284
We consider a thermodynamic system consisting ofn independent subsystems. Each subsystem is described by a HamiltonianH=H
0+
i
H
1,i=1, 2,...,n. We answer the question of how the entirety=(
1,
2,...,
n
) must be varied in order to change the total partition function and the total free energy of the system monotonically. 相似文献