共查询到20条相似文献,搜索用时 31 毫秒
1.
Chiral orbifold models are defined as gauge field theories with a finite gauge group Γ. We start with a conformal current
algebra associated with a connected compact Lie group G and a negative definite integral invariant bilinear form on its Lie algebra. Any finite group Γ of inner automorphisms or
(in particular, any finite subgroup of G) gives rise to a gauge theory with a chiral subalgebra of local observables invariant under Γ. A set of positive energy modules is constructed whose characters span, under some assumptions on Γ, a finite dimensional unitary representation of
. We compute their asymptotic dimensions
(thus singling out the nontrivial orbifold modules) and find explicit formulae for the modular transformations and hence,
for the fusion rules.
As an application we construct a family of rational conformal field theory (RCFT) extensions of W
1+∞ that appear to provide a bridge between two approaches to the quantum Hall effect.
Received: 5 December 1996 / Accepted: 1 April 1997 相似文献
2.
The reduction of a theory with gauge group G to a theory which is gauge invariant with respect to a subgroup H of G is formulated in a geometrical language. It is assumed that among the physical fields considered as cross-sections of fibre bundles with structure group G there exists a section of the fibre bundle with fibre isomorphic to G/H — a Higgs field. The investigation of the broken gauge symmetry is based on the reduction theorem for structure groups of principal fibre bundles. The reduction of fields and their covariant derivatives is studied. 相似文献
3.
S. S. Murzin 《JETP Letters》1998,67(3):216-221
The conductance of doped n-GaAs films is studied experimentally as a function of magnetic field and temperature in strong magnetic fields right up to
the quantum limit (ħωc = E
F). The Hall conductance G
xy is virtually independent of temperature T until the transverse conductance G
xx is quite large compared with e
2/h. In strong fields, when G
xx becomes comparable to e
2/h, G
xy starts to depend on T. The difference between the conductances G
xx at the two temperatures 4.2 and 0.35 K depends only weakly on the magnetic field H over a wide range of magnetic fields, while the conductances G
xx themselves vary strongly. The results can be explained by quantum corrections to the conductance as a result of the electron-electron
interaction in the diffusion channel. The possibility of quantization of the Hall conductance as a result of the electron-electron
interaction is discussed.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 3, 201–206 (10 February 1998) 相似文献
4.
W.M. Tulczyjew 《Reports on Mathematical Physics》1979,16(2):233-250
A geometric interpretation of gauge field for extended objects is given. This interpretation is a generalization of the interpretation of electrodynamics based on connections in principal fibre bundles. Only the geometry of gauge fields is formulated. Field dynamics and interaction of the fields with extended objects will be studied separately. 相似文献
5.
6.
《Nuclear Physics B》1995,444(3):577-601
Gauge-invariant BFV approach to geometric quantization is applied to the case of hermitian symmetric spaces G/H. In particular, gauge invariant quantization on the Lobachevski plane and sphere is carried out. Due to the presence of symmetry, master equations for the first-class constraints, quantum observables and physical quantum states are exactly solvable. BFV-BRST operator defines a flat G-connection in the Fock bundle over G/H. Physical quantum states are covariantly constant sections with respect to this connection and are shown to coincide with the generalized coherent states for the group G. Vacuum expectation values of the quantum observables commuting with the quantum first-class constraints reduce to the covariant symbols of Berezin. The gauge-invariant approach to quantization on symplectic manifolds synthesizes geometric, deformation and Berezin quantization approaches. 相似文献
7.
Ema Maia 《Letters in Mathematical Physics》1981,5(6):531-537
We consider an extension of the supersymmetry formalism in order to include gauge fields. We construct a fiber bundle P(M
4×{θ}, G) over the superspace with the gauge group as the structural group. We obtain the equations of interacting pure Yang-Mills
and massless Higgs fields, considering these fields as the components of the same gauge field. Moreover, by fixing a gauge
we generate a mass as a result of the supersymmetry breaking.
Supported by Instituto Nacional de Investigacao Cientifica (Lisboa). 相似文献
8.
By generalizing a model previously proposed, a classical nonrelativistic U(1)×U(1) gauge field model for the electromagnetic interaction of composite particles in (2+1) dimensions is constructed. The model
contains a Chern–Simons U(1) field and the electromagnetic U(1) field, and it describes both a composite boson system or a composite fermion one. The second case is considered explicitly.
The model includes a topological mass term for the electromagnetic field and interaction terms between the gauge fields. By
following the Dirac Hamiltonian formalism for constrained systems, the canonical quantization for the model is realized. By
developing the path integral quantization method through the Faddeev–Senjanovic algorithm, the Feynman rules of the model
are established and its diagrammatic structure is discussed. The Becchi–Rouet–Stora–Tyutin formalism is applied to the model.
The obtained results are compared with the ones corresponding to the previous model. 相似文献
9.
David Hestenes 《Foundations of Physics》1982,12(2):153-168
The generator of electromagnetic gauge transformations in the Dirac equation has a unique geometric interpretation and a unique extension to the generators of the gauge group SU(2) × U(1) for the Weinberg-Salam theory of weak and electromagnetic interactions. It follows that internal symmetries of the weak interactions can be interpreted as space-time symmetries of spinor fields in the Dirac algebra. The possibilities for interpreting strong interaction symmetries in a similar way are highly restricted. 相似文献
10.
Eric A Lord 《Pramana》1975,4(4):164-170
A new generalisation of Einstein’s theory is proposed which is invariant under conformal mappings. Two scalar fields are introduced
in addition to the metric tensor field, so that two special choices of gauge are available for physical interpretation, the
‘Einstein gauge’ and the ‘atomic gauge’. The theory is not unique but contains two adjustable parameters ζ anda. Witha=1 the theory viewed from the atomic gauge is Brans-Dicke theory (ω=−3/2+ζ/4). Any other choice ofa leads to a creation-field theory. In particular the theory given by the choicea=−3 possesses a cosmological solution satisfying Dirac’s ‘large numbers’ hypothesis. 相似文献
11.
I. Schmelzer 《Foundations of Physics》2009,39(1):73-107
We present the bundle (Aff(3)⊗ℂ⊗Λ)(ℝ3), with a geometric Dirac equation on it, as a three-dimensional geometric interpretation of the SM fermions. Each (ℂ⊗Λ)(ℝ3) describes an electroweak doublet. The Dirac equation has a doubler-free staggered spatial discretization on the lattice
space (Aff(3)⊗ℂ)(ℤ3). This space allows a simple physical interpretation as a phase space of a lattice of cells.
We find the SM SU(3)
c
×SU(2)
L
×U(1)
Y
action on (Aff(3)⊗ℂ⊗Λ)(ℝ3) to be a maximal anomaly-free gauge action preserving E(3) symmetry and symplectic structure, which can be constructed using two simple types of gauge-like lattice fields: Wilson
gauge fields and correction terms for lattice deformations.
The lattice fermion fields we propose to quantize as low energy states of a canonical quantum theory with ℤ2-degenerated vacuum state. We construct anticommuting fermion operators for the resulting ℤ2-valued (spin) field theory.
A metric theory of gravity compatible with this model is presented too. 相似文献
12.
K. Mkrtchyan 《Physics of Particles and Nuclei Letters》2011,8(3):266-271
The explicit form of linearized gauge arid generalized “Weyl invariant” interactions of scalar and general higher even spin
fields in the AdS
D
space constructed in [1] is reviewed. Also a linearized interaction of vector field with general higher even spin, gauge
field is obtained. It is shown that the gauge invariant action of linearized vector field interacting with the higher spin
field also includes the whole tower of invariant actions for couplings of the same vector field with the gauge fields of smaller
even spin. 相似文献
13.
I. M. Dubrovskii 《Journal of Experimental and Theoretical Physics》1997,84(3):525-530
The behavior of a straight Abrikosov vortex in an anisotropic uniaxial London superconductor is studied. Analytical expressions
are derived that approximately describe the magnetic field in three regions: the asymptotic region, where the distance r from the vortex line is greater than λΓ (λ is the London length and Γ is the anisotropy constant), the intermediate region λ<r<λΓ, and the region r<λ. It is found that in the intermediate region with high anisotropy the component of the magnetic field along the vortex line
changes sign for a certain interval of angles between the vortex line and the anisotropy axis. Because of this the interaction
of parallel vortices whose plane is parallel to the anisotropy axis has a minimum and a maximum. This means that numerous
metastable vortex lattices can exist. Additional terms in the vortex self-energy are obtained, and although they are smaller
than the leading logarithmic term, they display a different dependence on the angle between the vortex line and the anisotropy
axis.
Zh. éksp. Teor. Fiz. 111, 954–963 (March 1997) 相似文献
14.
15.
P. N. Shankar 《Pramana》2005,65(3):437-455
We consider in a frame fixed to a bubble translating with steady speedU, the inviscid, axisymmetric, irrotational motion of the liquid past it. If all speeds are normalized byU and lengths by {ie437-1}, whereT is the surface tension of the liquid-bubble interface, it can be shown that the unknown bubble shape and field depend on
a single parameter {ie437-2} alone, where the pressures are the ones in the bubble and far away respectively. WhenΓ is very large the bubble is almost spherical in shape while for Γ<- Γ* ≈ -0.315, bubbles whose exteriors are simply connected do not exist. We solve the non-linear, free boundary problem for the
whole range Γ* < Γ < ∞ by the use of an analytical representation for the bubble shape, a surface singularity method to compute potential
flows and a generalized Newton’s method to continue inΓ. Apart from providing explicit representations for bubble shapes and detailed numerical values for the bubble parameters,
we show that the classical linearized solution for largeΓ is a very good approximation, surprisingly, to as low values of Γ as 2. We also show that Miksiset al [1] is inaccurate over the whole range and in serious error for large and smallΓ. These have been corrected. 相似文献
16.
Tatiana A. Ivanova Olaf Lechtenfeld Alexander D. Popov Thorsten Rahn 《Letters in Mathematical Physics》2009,89(3):231-247
We consider the Yang–Mills flow equations on a reductive coset space G/H and the Yang–Mills equations on the manifold
\mathbbR×G/H{\mathbb{R}\times G/H}. On non-symmetric coset spaces G/H one can introduce geometric fluxes identified with the torsion of the spin connection. The condition of G-equivariance imposed on the gauge fields reduces the Yang–Mills equations to f4{\phi^4}-kink equations on
\mathbbR{\mathbb{R}}. Depending on the boundary conditions and torsion, we obtain solutions to the Yang–Mills equations describing instantons,
chains of instanton–anti-instanton pairs or modifications of gauge bundles. For Lorentzian signature on
\mathbbR×G/H{\mathbb{R}\times G/H}, dyon-type configurations are constructed as well. We also present explicit solutions to the Yang–Mills flow equations and
compare them with the Yang–Mills solutions on
\mathbbR×G/H{\mathbb{R}\times G/H}. 相似文献
17.
In a previous paper [3], we showed how certain orientations of the edges of a graph Γ embedded in a closed oriented surface Σ can be understood as discrete spin structures on Σ. We then used this correspondence to give a geometric proof of the Pfaffian formula for the partition function of the dimer
model on Γ. In the present article, we generalize these results to the case of compact oriented surfaces with boundary. We also show
how the operations of cutting and gluing act on discrete spin structures and how they change the partition function. These
operations allow to reformulate the dimer model as a quantum field theory on surface graphs. 相似文献
18.
D. J. Cirilo-Lombardo 《Physics of Particles and Nuclei Letters》2011,8(6):507-511
We analyze in this letter the same space-time structure as that presented in our previous reference (Part. Nucl., Lett. 2010.
V. 7, No. 5, P. 299–307), but relaxing now the condition a priori of the existence of a potential for the torsion. We show
through exact cosmological solutions from this model, where the geometry is Euclidean R ⊗ O
3 ∼ R ⊗ SU(2), the relation between the space-time geometry and the structure of the gauge group. Precisely this relation is directly
connected with the relation between the spin and torsion fields. The solution of this model is explicitly compared with our
previous ones and we find that: (i) the torsion is not identified directly with the Yang-Mills type strength field, (ii) there
exists a compatibility condition connected with the identification of the gauge group with the geometric structure of the
space-time: this fact leads to the identification between derivatives of the scale factor with the components of the torsion
in order to allow the Hosoya-Ogura ansatz (namely, the alignment of the isospin with the frame geometry of the space-time),
and (iii) of two possible structures of the torsion the “tratorial” form (the only one studied here) forbids wormhole configurations,
leading only to cosmological space-time solution in eternal expansion. 相似文献
19.
Dominic G. B. Edelen 《International Journal of Theoretical Physics》1986,25(7):671-684
Homogeneous scaling of the group space of the Poincaré group,P
10, is shown to induce scalings of all geometric quantities associated with the local action ofP
10. The field equations for both the translation and the Lorentz rotation compensating fields reduce toO(1) equations if the scaling parameter is set equal to the general relativistic gravitational coupling constant 8Gc
–4. Standard expansions of all field variables in power series in the scaling parameter give the following results. The zeroth-order field equations are exactly the classical field equations for matter fields on Minkowski space subject to local action of an internal symmetry group (classical gauge theory). The expansion process is shown to breakP
10-gauge covariance of the theory, and hence solving the zeroth-order field equations imposes an implicit system ofP
10-gauge conditions. Explicit systems of field equations are obtained for the first- and higher-order approximations. The first-order translation field equations are driven by the momentum-energy tensor of the matter and internal compensating fields in the zeroth order (classical gauge theory), while the first-order Lorentz rotation field equations are driven by the spin currents of the same classical gauge theory. Field equations for the first-order gravitational corrections to the matter fields and the gauge fields for the internal symmetry group are obtained. Direct Poincaré gauge theory is thus shown to satisfy the first two of the three-part acid test of any unified field theory. Satisfaction of the third part of the test, at least for finite neighborhoods, seems probable. 相似文献
20.
Suppose given a complex projective manifold M with a fixed Hodge form Ω. The Bohr-Sommerfeld Lagrangian submanifolds of (M,Ω) are the geometric counterpart to semi-classical physical states, and their geometric quantization has been extensively studied. Here we revisit this theory in the equivariant context, in the presence of a compatible (Hamiltonian) action of a connected compact Lie group. 相似文献