共查询到20条相似文献,搜索用时 15 毫秒
1.
A. Bartl W. Majerotto B. Mösslacher N. Oshimo 《Zeitschrift fur Physik C Particles and Fields》1991,52(4):677-684
We present a detailed study of
and
and the subsequent decays of
,
, and
at the LHC
. We explore the relevant supersymmetry parameter range. We calculate the cross sections as well as the rates for interesting signatures such as the production of one or two leptons on the lepton side. 相似文献
2.
We have examined the influence of parametric noise on the solution behavioru(t, x) of a nonlinear initial value() problem arising in cell kinetics. In terms of ensemble statistics, the eventual limiting solution mean
and variance
are well-characterized functions of the noise statistics, and
and
depend on . When noise is continuously present along the trajectory,
and
are independent of the noise statistics and . However, in their evolution toward
and
, both
u
(t, x) and
u
2
(t, x) depend on the noise and. 相似文献
3.
Two functionals
and
are introduced forC
*-dynamical systems with invariant states and stationary channels. It is shown that the Kolmogorov-Sinai-type theorems hold for these functionals
and
. Our functionals
and
are set within the framework of quantum information theory and generalize a quantum KS entropy by CNT and the mutual entropy by Ohya. 相似文献
4.
It is shown that solvable mixed spin ladder models can be constructed from su(N) permutators. Heisenberg rung interactions appear as chemical potential terms in the Bethe Ansatz solution. Explicit examples given are a mixed spin-
spin-1 ladder, a mixed spin-
spin-
ladder and a spin-1 ladder with biquadratic interactions. 相似文献
5.
An approximation procedure for the solution of stochastic nonlinear equations, which was derived from a variational principle in a previous paper, is applied to the problem of a particle that diffuses in a symmetric bistable potential starting from the point of unstable equilibrium. The second moment
and variance
for the particle's position
are calculated as functions of the timet. Good agreement is found with results recently obtained by Baibuzet al. from an approximate evaluation of a path integral expression for the probability density. 相似文献
6.
A renormalization group method is used to construct approximants for the magnetization,m, and the static structure factor,
(q), for the simple cubic Ising model. Using the best values for the thermal critical index, the transition temperature, and the nearest-neighbor correlation function as input, we obtain recursion relations form and
(q) which lead to reasonable results over a wide range of temperatures and wave numbers. 相似文献
7.
Pierluigi Contucci 《Journal of statistical physics》1996,82(5-6):1647-1657
We study the coexistence phase in the two-dimensional Ising model. Optimizing the cluster expansion technique, we are able to prove the phase separation phenomenon, with the Onsager value for the surface tension, in a range
, where
estimates from above the critical within 19% and essentially coincides with the entropic bound. 相似文献
8.
Domingos H. U. Marchetti 《Journal of statistical physics》1990,61(3-4):909-911
A simple argument is presented by which one can show that the critical inverse temperature
c
of a two-dimensional Coulomb gas (standard or hard-core) with activityz satisfies
, where
in the low-activity limit. Previous results yield
. 相似文献
9.
S. L. Woronowicz 《Communications in Mathematical Physics》1972,28(3):221-235
Let
be aC*-algebra and
be an opposite algebra. Notions of exact andj-positive states of
are introduced. It is shown, that any factor state of
can be extended to a pure exactj-positive state
of
. The correspondence
generalizes the notion of the purifications map introduced by Powers and Størmer. The factor states 1 and 2 are quasi-equivalent if and only if their purifications
and
are equivalent. 相似文献
10.
Sergio Doplicher Daniel Kastler Derek W. Robinson 《Communications in Mathematical Physics》1966,3(1):1-28
Starting from aC*-algebra
and a locally compact groupT of automorphisms of
we construct a covariance algebra
with the property that the corresponding *-representations are in one-to-one correspondence with covariant representations of
i.e. *-representations of
in which the automorphisms are continuously unitarily implemented. We further construct for relativistic field theory an algebra
yielding the *-representations of
in which the space time translations have their spectrum contained inV. The problem of denumerable occurence of superselection sectors is formulated as a condition on the spectrum of
. Finally we consider the covariance algebra
built with space translations alone and show its relevance for the discussion of equilibrium states in statistical mechanics, namely we restore in this framework the equivalence of uniqueness of the vacuum, irreducibility and a weak clustering property.On leave of absence from Istituto di Fisica G. Marconi — Roma. 相似文献
11.
We study analogues of the Yangian of the Lie algebra
for the other classical Lie algebras
and
. We call them twisted Yangians. They are coideal subalgebras in the Yangian of
and admit homomorphisms onto the universal enveloping algebras U(
) and U(
) respectively. In every twisted Yangian we construct a family of maximal commutative subalgebras parametrized by the regular semisimple elements of the corresponding classical Lie algebra. The images in U(
) and U(
) of these subalgebras are also maximal commutative. 相似文献
12.
We study the time evolution of two configurations of the Ising model submitted to heat-bath (HB), Glauber (G), and two types of Metropolis (M and
) dynamics, analyzing the damage spreading on a square lattice. We find that the damages produced by the dynamics G and M are greater than those resulting from HB and
dynamics. We also observe that, only for zero magnetic field, the damages of the dynamics G and M seem to be numerically equivalent. 相似文献
13.
Marcus Pivato 《Journal of statistical physics》2003,110(1-2):247-267
If
, and
is a finite (nonabelian) group, then
is a compact group; a multiplicative cellular automaton (MCA) is a continuous transformation
which commutes with all shift maps, and where nearby coordinates are combined using the multiplication operation of
. We characterize when MCA are group endomorphisms of
, and show that MCA on
inherit a natural structure theory from the structure of
. We apply this structure theory to compute the measurable entropy of MCA, and to study convergence of initial measures to Haar measure. 相似文献
14.
W. Drechsler 《Foundations of Physics》1989,19(12):1479-1497
To represent extension of objects in particle physics, a modified Weyl theory is used by gauging the curvature radius of the local fibers in a soldered bundle over space-time possessing a homogeneous space G/H of the (4, 1)-de Sitter group G as fiber. Objects with extension determined by a fundamental length parameter R0 appear as islands D(i) in space-time characterized by a geometry of the Cartan-Weyl type (i.e., involving torsion and modified Weyl degrees of freedom). Farther away from the domains D(i), space-time is identified with the pseudo-Riemannian space of general relativity. Extension and symmetry breaking are described by a set of additional fields (
, given as a section on an associated bundle
over space-time B with structural group
= G D(1), where D(1) is the dilation group. Field equations for the quantities defining the underlying bundle geometry and for the fields
are established involving matter source currents derived from a generalized spinor wave function. Einstein's equations for the metric are regarded as the part of the
-gauge theory related to the Lorentz subgroup H of G exhibiting thereby the broken nature of the
-symmetry for regions outside the domains D(i).Talk presented at the International Conference on Field Theory and General Relativity held at Utah State University, Logan, Utah, June 26–July 2, 1988. 相似文献
15.
We display three equivalent conditions for a sublattice, isomorphic to aP
, of the propositional systemP() of a quantum system to be the representation of a physical subsystem (see [1]). These conditions are valid for dim
3. We prove that one of them is still necessary and sufficient if dim
<3. A physical interpretation of this condition is given.Wetenschappelijke medewerkers bij het Interuniversitair Instituut voor Kernwetenschappen (in het kader van navorsingsprogramma 21 EN). 相似文献
16.
Fukui Guo Yufeng Zhang Qingyou Yan 《International Journal of Theoretical Physics》2004,43(4):1139-1146
A new simple method for obtaining integrable hierarchies of soliton equations is proposed. First of all, a new loop algebra
is constructed, whose commutation operation is clear as that in loop algebra
. Second, by making use of the Tu scheme, many of integrable hierarchies with multicomponent potential functions can be produced. As a specific application of our method, a multicomponent AKNS hierarchy is obtained. Finally, an expanding loop algebra
of the loop algebra
is constructed. Taking advantage of
above, a type of integrable coupling system of the multicomponent AKNS hierarchy is worked out. 相似文献
17.
Given a simple, simply laced, complex Lie algebra
corresponding to the Lie group G, let
be thesubalgebra generated by the positive roots. In this Letter we construct aBV algebra
whose underlying graded commutative algebra is given by the cohomology, with respect to
, of the algebra of regular functions on G with values in
. We conjecture that
describes the algebra of allphysical (i.e., BRST invariant) operators of the noncritical
string. The conjecture is verified in the two explicitly known cases,
2 (the Virasoro string) and
3 (the
string). 相似文献
18.
R. Fantoni F. Bijnen N. Djurić S. Piccirillo 《Applied physics. B, Lasers and optics》1991,52(3):176-183
Coherent anti-Stokes Raman Scattering has been employed to investigate gas-phase reactions between SiH4 and small hydrocarbons leading to formation of SiC powder. SiC2 has been identified as reaction intermediate, due to the occurrence of resonance enhanced CARS coupling vibrational leavels in the ground
and first electronically excited
state. The rich structure observed in the range 4480 Å<AS<4650 Å is assigned to SiC2 taking into account the cyclic geometry of this species and revising former data on
electronic transitions.ENEA Guest 相似文献
19.
An account is given of the structure and representations of chiral bosonic meromorphic conformal field theories (CFT's), and, in particular, the conditions under which such a CFT may be extended by a representation to form a new theory. This general approach is illustrated by considering the untwisted andZ
2-twisted theories, () and
respectively, which may be constructed from a suitable even Euclidean lattice . Similarly, one may construct lattices
and
by analogous constructions from a doubly-even binary code
. In the case when
is self-dual, the corresponding lattices are also. Similarly, () and
are self-dual if and only if is. We show that
has a natural triality structure, which induces an isomorphism
and also a triality structure on
. For
the Golay code,
is the Leech lattice, and the triality on
is the symmetry which extends the natural action of (an extension of) Conway's group on this theory to the Monster, so setting triality and Frenkel, Lepowsky and Meurman's construction of the natural Monster module in a more general context. The results also serve to shed some light on the classification of self-dual CFT's. We find that of the 48 theories () and
with central charge 24 that there are 39 distinct ones, and further that all 9 coincidences are accounted for by the isomorphism detailed above, induced by the existence of a doubly-even self-dual binary code. 相似文献
20.
We show that the Ashtekar-Isham extension
of the configuration space of Yang-Mills theories
is (topologically and measure-theoretically) the projective limit of a family of finite dimensional spaces associated with arbitrary finite lattices.These results are then used to prove that
is contained in a zero measure subset of
with respect to the diffeomorphism invariant Ashtekar-Lewandowski measure on
. Much as in scalar field theory, this implies that states in the quantum theory associated with this measure can be realized as functions on the extended configuration space
. 相似文献