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1.
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
2.
For the non-compact abelian lattice Higgs model in Landau gauge Kennedy and King (Princeton preprint, 1985) showed that the two point function
does not decay in the Higgs phase. We generalize their methods to show that for the same range of parameters there are states parametrized by an angle [0, 2) such that
and
0$$
" align="middle" border="0">
. 相似文献
3.
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
4.
J. Nowotny M. Rekas W. Weppner 《Applied Physics A: Materials Science & Processing》1988,47(2):205-208
Thermoelectric power (TP) and electrical conductivity (EC) measurements were performed for YEa2Cu3Ox at 1128 K under controlled oxygen partial pressure varying between 50 and 105 Pa. Three regimes are observed for the electrical properties. At low
both TP and EC remain constant with
. In the medium range
sharp changes of both electrical parameters occur; TP changes sign from positive above 4×102 Pa to negative below this
value. In the high
region (>7.6×103 Pa) TP vs log
exhibits two slopes; 5.1 below 1.5×104 Pa and 8.4 above this
value. The slopes can be discussed in terms of the defect structure involving singly and doubly ionized oxygen vacancies below and above 7.6×103 Pa, respectively. 相似文献
5.
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
6.
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
7.
We consider the Dirichlet Laplacian for astrip in
with one straight boundary and a width
, where $f$ is a smooth function of acompact support with a length 2b. We show that in the criticalcase,
, the operator has nobound statesfor small
.On the otherhand, a weakly bound state existsprovided
. In thatcase, there are positive c
1,c
2 suchthat the corresponding eigenvalue satisfies
for all
sufficiently small. 相似文献
8.
B. Enriquez 《Communications in Mathematical Physics》1995,170(1):197-206
We propose a quantum lattice version of B. Feigin and E. Frenkel's constructions, identifying the KdV differential polynomials with functions on a homogeneous space under the nilpotent part of
. We construct an action of the nilpotent part
of
on their lattice counterparts, and embed the lattice variables in a
, coinduced from a quantum version of the principal commutative subalgebra, which is defined using the identification of
with its dual algebra. 相似文献
9.
Bill Dalton 《International Journal of Theoretical Physics》1984,23(8):751-769
We study those nonlinear infinitesimal realizations ofSL(2,C) that leave invariant the quadratic function
of the four-velocity components of a particle. These transformations are defined as maps of a larger manifold, which includes the four-velocity space, into itself in such a way that transformations of the
depend upon other functions in the manifold. The requirement that
remain invariant limits the types of other functions that can contribute in the transformation of the
. However, among those allowed are the spinors and a three-dimensional space that transforms nonlinearly and recently associated with electric charge. We point out and explore two interesting aspects of these nonlinear realizations. First, they generally necessitate interactions since
is not a covariant equation. Second, with superposition of solutions, exact measurement of the four-velocity or space-time position, is impossible. This and related features of nondeterministic measurement inherent to these realizations are discussed. 相似文献
10.
Toshiharu Kawai 《General Relativity and Gravitation》1986,18(10):995-1018
We develop a gauge theory of gravity on the basis of the principal fiber bundle over the four-dimensional space-timeM with the covering groupP¯
0
of the proper orthochronous Poincaré group. The field components
are constructed with the connection coefficients
,
and with a Higgs-type field. A Lorentz metricg is introduced with
, which are then identified with the components of duals of the Vierbein fields. Associated with there is a spinor structure onM. For Lagrangian densityL, which is a function of
,
,, matter field , and oftheir first derivatives, we give the conditions imposed by the requirement of the
gauge invariance. The Lagrangian densityL is restricted to be of the formL =L
tot
(, T
klm
,R
klmn
,
k
, ), in whichT
klm
,R
klmn
are the field strengths of
,
, respectively. Identities and conservation laws following from the
gauge invariance are given. Particularly noteworthy is the fact that the energy momentum conservation law follows from theinternal translational invariance. The field equation of is automatically satisfied, if those of
and of are both satisfied. The possible existence of matter fields with intrinsic energy momentum is pointed out. When is a field with vanishing intrinsic energy momentum, the present theory practically agrees with the conventional Poincaré gauge theory of gravity, except for the seemingly trivial terms in the expression of the spin-angular momentum density. A condition leading to a Riemann-Cartan space-time is given. The field holds a key position in the formulation. 相似文献
11.
We classify the finite-dimensional irreducible representations of the quantum affine algebra
in terms of highest weights (this result has a straightforward generalization for arbitrary quantum affine algebras). We also give an explicit construction of all such representations by means of an evaluation homomorphism
, first introduced by M. Jimbo. This is used to compute the trigonometricR-matrices associated to finite-dimensional representations of
. 相似文献
12.
F. Ylli Y. Gros C. Meyer F. Hartmann-Boutron P. Strobel M. Novak J. L. Tholence 《Hyperfine Interactions》1994,93(1):1727-1731
Comparison of RT Mössbauer spectra of samples prepared with low
and high
suggests incomplete oxygenation of low
samples. At lowT, the magnetic hfs appears very gradually, without hf anomalies. 相似文献
13.
We develop a geometrical structure of themanifolds and
associated, respectively, withgauge symmetry and BRST symmetry. Then, we show that
, where
is the group of BRST transformations, is endowed with the structureof a principal fiber bundle over the base manifold. Furthermore, in this geometricalsetup, due to the nilpotency of the BRST operator, weprove that the effective action of a gauge theory is aBRST-exact term up to the classical action. Then, weconclude that the effective action where only the gaugesymmetry is fixed is cohomologically equivalent to the action where the gauge and the BRSTsymmetries are fixed. 相似文献
14.
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
15.
We formulate the equilibrium correlation functions for local observables of an assembly of non-relativistic, neutral gravitating fermions in the limit where the number of particles becomes infinite, and in a scaling where the region , to which they are confined, remains fixed. We show that these correlation functions correspond, in the limit concerned, to states on the discrete tensor product
, where the
are copies of the gauge invariantC*-algebra
of the CAR overL
2(R
3). The equilibrium states themselves are then given by
, where
, is the Gibbs state on
for an infinitely extended ideal Fermi gas at density , and where 0 is the normalised density function that minimises the Thomas-Fermi functional, obtained in [2], governing the equilibrium thermodynamics of the system. 相似文献
16.
H. C. Hsieh 《International Journal of Infrared and Millimeter Waves》1981,2(1):131-147
The expression for free carrier Faraday rotation and for ellipticity , as the function of the applied parallel static electric field
and static magnetic field
for a given value of wave angular frequency and electron concentration N0, are obtained and theoretically analyzed with the aid of one-dimensional linearized wave theory and Kane's non-parabolic isotropic dispersion law. It is shown that the maximum Faraday rotation occurs near the cyclotron resonance condition, which can be expressed as
, where
,
, and
. Here m* and e denote the effective mass and charge of electron, respectively. g is the forbidden bandgap of semiconductor. v0 is the carrier drift velocity, which is a non-linear function of E0 in high field condition. A possibility of a simple way of determining the non-linear v0 vs E0 characteristics of semiconductors by the measurement of Faraday rotation is also discussed. 相似文献
17.
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
18.
Sergio Doplicher Rudolf Haag John E. Roberts 《Communications in Mathematical Physics》1969,15(3):173-200
We wish to study the construction of charge-carrying fields given the representation of the observable algebra in the sector of states of zero charge. It is shown that the set of those covariant sectors which can be obtained from the vacuum sector by acting with localized automorphisms has the structure of a discrete Abelian group. An algebra of fields
can be defined on the Hilbert space of a representation of the observable algebra
which contains each of the above sectors exactly once. The dual group of acts as a gauge group on
in such a way that
is the gauge invariant part of
is made up of Bose and Fermi fields and is determined uniquely by the commutation relations between spacelike separated fields. 相似文献
19.
A. G. Lipnitskii A. V. Nikiforov V. M. Silkin E. V. Chulkov 《Russian Physics Journal》1991,34(10):888-893
The surface electronic band structure of the Pb (001) was calculated using the self-consistent, first-principles linear-augmented-plane-wave method and the norm-conserving pseudopotentiai method. In the nonrelativistic case, forbidden gaps appear above and below the Fermi levelin the bulk projected band structure of lead. An occupied surface state at the
point and two surface states in a wide forbidden gap above EF are found. A characteristic feature of the electronic structure of the Pb (001) surface is the absence of a surface state within the forbidden S-P gap in the vicinity of the
point. The inclusion of scalar-relativistic effects leads to the merger of several S-P gaps into one wide gap extending throughout the entire Brillouin zone. At the same time, the occupied state at point
extends to point
and its energy decreases by 2 eV. New, relatively weak surface states in the
direction and unoccupied states in the vicinity of the
point appear. An unoccupied surface state is found at the bottom of the forbidden gap at point
. Including the contribution of the spinorbit pseudopotentiai leads to the appearance of two-spin orbit gas; however, the surface level structure is practically unchanged (except for the disappearance of the unoccupied surface state of Pz-symmetry at point
).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 47–53, October, 1991. 相似文献
20.
James D. Edmonds Jr. 《Foundations of Physics》1978,8(5-6):439-444
The 2-by-2 Pauli matrix algebra is used to write the 1-by-4 Dirac field in anequivalent 2-by-2 matrix . The current 4-vectors
and *µ are then compared and the latter is shown to not be easily interpretable as a probability density, and also tocontain
. 相似文献