共查询到20条相似文献,搜索用时 15 毫秒
1.
Mirko Degli Esposti Sandro Graffi Stefano Isola 《Communications in Mathematical Physics》1995,167(3):471-507
The canonical quantization of any hyperbolic symplectomorphismA of the 2-torus yields a periodic unitary operator on aN-dimenional Hilbert space,N=1/h. We prove that this quantum system becomes ergodic and mixing at the classical limit (N,N prime) which can be interchanged with the time-average limit. The recovery of the stochastic behaviour out of a periodic one is based on the same mechanism under which the uniform distribution of the classical periodic orbits reproduces the Lebesgue measure: the Wigner functions of the eigenstates, supported on the classical periodic orbits, are indeed proved to become uniformly speread in phase space. 相似文献
2.
The structure of the automorphism group of a simple C*-algebra of real rank zero which is an inductive limit of circle algebras is described. In particular, it is proved that the automorphism group of the irrational rotation C*-algebra,A
, for any irrational number , is an extension of a topologically simple group by GL2().Dedicated to Huzihiro Araki 相似文献
3.
James McConnell 《Physica A》1984,128(3):611-630
A procedure is proposed for calculating in Debye approximation physical quantities related to steady state random thermal motion. The results are expressed in terms of the stochastic rotation operator. Explicit expressions are derived for this operator and its ensemble average in the case of a rotating molecule which is modelled as a sphere, linear rotator or asymmetric rotator. The relevance of these expressions for certain dielectric and nuclear magnetic relaxation processes is considered. 相似文献
4.
A. Kishimoto 《Reports on Mathematical Physics》1979,15(1):21-26
We study primary states of the CAR algebra which are left invariant under quasi-free automorphisms αU corresponding to unitaries U of a von Neumann algebra on the one-particle Hilbert space, and show that they are quasi-free states ?A corresponding to self-adjoint operators A in ′ with 0 ? A ? 1, under the assumption that does not contain any finite type Ifactor direct summands. Next we study automorphisms of the CAR algebra which commute with αU for U in a von Neumann algebra and show that they are quasi-free automorphisms αU with U in ′ under the same assumption on as above. Finally by using the latter result we obtain a generalization of a theorem of Hugenholtz and Kadison [3]. 相似文献
5.
On invariant states and the commutant of a group of quasi-free automorphisms of the CAR algebra. III
Akitaka Kishimoto 《Reports on Mathematical Physics》1979,16(1):121-124
It is shown that a state of the CAR algebra is an extreme invariant state under the group of quasi-free automorphisms αU with unitaries u in a von Neumann algebra M on the one- particle Hilbert space if and only if it is a gauge-invariant quasi-free state Ø A corresponding to A in M' with 0 ≤ A ≤ 1, under the assumption that M does not contain any finite type I factor direct summands. 相似文献
6.
The effect of a parallel magnetic field on superconducting two-leg ladders is investigated numerically. The magnetization curve displays an irrational plateau at a magnetization equal to the hole density. Remarkably, its stability is fundamentally connected to the existence of a well-known magnetic resonant mode. Once the zero-field spin gap is suppressed by the field, pairs acquire a finite momentum characteristic of a Fulde-Ferrell-Larkin-Ovchinnikov phase. In addition, Sz = 0 triplet superconducting correlations coexist with singlet ones above the irrational plateau. This provides a simple mechanism in which the Pauli limit is exceeded as suggested by recent experiments. 相似文献
7.
Dénes Petz 《Letters in Mathematical Physics》1992,24(3):211-220
The central limit theorem of Cushen and Hudson is reformulated on the algebra of the CCR. Namely, for a gauge invariant state , the weighted convolutions
n
of the central limit tend to the quasi-free reduction
Q
of pointwise. It is proved that if the initial relative entropy S(,
Q
) is finite, then S(
n
,
Q
) goes to 0 and so
n
–
Q
0. No restriction on the dimension of the test function space is made. 相似文献
8.
Reversed rotation of limit cycle oscillation and dynamics of low-intermediate-high confinement transition
下载免费PDF全文

The dynamics of the confinement transition from L mode to H mode(LH) is investigated in detail theoretically via the extended three-wave coupling model describing the interaction of turbulence and zonal flow(ZF) for the first time.Thereinto, turbulence is divided into a positive-frequency(PF) wave and a negative-frequency(NF) one, and the gradient of pressure is added as the auxiliary energy for the system. The LH confinement transition is observed for a sufficiently high input energy. Moreover, it is found that the rotation direction of the limit cycle oscillation(LCO) of PF wave and pressure gradient is reversed during the transition. The mechanism is illustrated by exploring the wave phases. The results presented here provide a new insight into the analysis of the LH transition, which is helpful for the experiments on the fusion devices. 相似文献
9.
U. Cattaneo 《Communications in Mathematical Physics》1969,13(3):226-245
We use cohomology of Lie algebras to analyse the abelian extensions of the Poincaré algebraP. We study particularly the irreducible and truly irreducible extensions: some irreducibility criteria are proved and applied to obtain a classification of types of irreducible abelian extensions ofP. We give a characterization of the minimal essential extensions in terms of truly irreducible extensions. 相似文献
10.
U. Cattaneo 《Communications in Mathematical Physics》1971,20(3):220-244
We analyse the extensions of the Poincaré algebraP with arbitrary kernels. The main tool is a reduction theorem which generalizes the Hochschild-Serre theorem forn=2. This reduction theorem is proved and used to investigate the structure of the Lie algebras obtained by extension.We look particularly for the irreducible and -irreducible extensions ofP and we classify the types of irreducible extensions with arbitrary kernels. 相似文献
11.
We determine the structure of two variations on the Temperley-Lieb algebra, both used for dealing with special kinds of boundary conditions in statistical mechanics models. The first is a new algebra, the blob algebra. We determine both the generic and all the exceptional structures for this two parameter algebra. The second is the periodic Temperley-Lieb algebra. The generic structure and part of the exceptional structure of this algebra have already been studied. We complete the analysis using results from the study of the blob algebra. 相似文献
12.
M. Fannes 《Communications in Mathematical Physics》1976,51(1):55-66
We show that any automorphism of the CCR algebra, leaving the quasi-free states globally invariant, is monoparticular.Aspirant van het Belgisch N.F.W.O. On leave from University of Leuven K.U.L. (Belgium). Partially supported by F.O.M. 相似文献
13.
Klaus Fredenhagen 《Communications in Mathematical Physics》1977,52(3):255-266
The implementability of automorphisms and derivations of the CAR-algebra in a pure quasifree state is discussed in detail. Especially the properties of the implementing operators are investigated, and an explicit construction is given. Extending a result from [2] for the CCR-algebra, we get a new necessary condition for a derivation to be implementable by a selfadjoint operator. 相似文献
14.
The group of automorphisms of the Galilei groupG: Aut(G) is calculated. It is shown that Aut(G) has the structure of a semi-direct product byG of the group ? m * ×?m where ?m is the group of reals noted multiplicatively and ? m * m is the subgroup of positive reals. 相似文献
15.
The dynamical entropy of quasifree automorphisms and quasifree states is caalculated and shown to be the entropy of the shift created by the group velocity. Some continuity properties are proved. 相似文献
16.
The group of automorphisms of the Galilei groupG: Aut(G) is calculated. It is shown that Aut(G) has the structure of a semi-direct product byG of the group
m
*
×m where m is the group of reals noted multiplicatively and
m
*
<m is the subgroup of positive reals. 相似文献
17.
The theorem that each derivation of aC*-algebra
extends to an inner derivation of the weak-operator closure (
)– of
in each faithful representation of
is proved in sketch and used to study the automorphism group of
in its norm topology. It is proved that the connected component of the identity in this group contains the open ball of radius 2 with centerl and that each automorphism in extends to an inner automorphism of (
)–.Research conducted with the partial support of the NSF and ONR. 相似文献
18.
Erling Størmer 《Communications in Mathematical Physics》1974,36(2):115-122
It is first shown that a *-automorphism of a factor is inner if and only if it is asymptotically equal to the identity automorphism. Then it is shown that a periodic *-automorphism of a von Neumann algebra is inner if and only if its fixed point algebra is a normal subalgebra of . 相似文献
19.
S. A. Adeleke 《International Journal of Theoretical Physics》1989,28(4):469-479
It is shown that discontinuous automorphisms of the proper Galilei and Euclidean groups (i.e., without space inversions) exist in three dimensions, but not in higher dimensions. 相似文献
20.
We compute the entropyh
A
(
U
) in the sense of Connes, Narnhofer and Thirring of Bogoliubov automorphisms
U
of the CAR-algebra with respect to invariant quasifree states
A
with 0A1 having pure point spectrum.Supported in part by a grant from the National Science Foundation 相似文献