406 research outputs found
Chiral Perturbation Theory in the Framework of Non-Commutative Geometry
We consider the non-commutative generalization of the chiral perturbation
theory. The resultant coupling constants are severely restricted by the model
and in good agreement with the data. When applied to the Skyrme model, our
scheme reproduces the non-Skyrme term with the right coefficient. We comment on
a similar treatment of the linear -model.Comment: In this revised manuscript, we alter one of the conclusion
2-d Gravity as a Limit of the SL(2,R) Black Hole
The transformation of the black hole under a boost of the
subgroup U(1) is studied. It is found that the tachyon vertex operators of the
black hole go into those of the conformal field theory coupled to
gravity. The discrete states of the black hole also tend to the discrete states
of the 2-d gravity theory. The fate of the extra discrete states of the black
hole under boost are discussed.Comment: LaTeX file, 14 page
Vector-Chiral Equivalence in Null Gauged WZNW Theory
We consider the standard vector and chiral gauged WZNW models by their gauged
maximal null subgroups and show that they can be mapped to each other by a
special transformation. We give an explicit expression for the map in the case
of the classical Lie groups , , , , and note its
connection with the duality map for the Riemmanian globally symmetric spaces.Comment: 13 pages, LaTe
A Unified Scheme for Modular Invariant Partition Functions of WZW Models
We introuduce a unified method which can be applied to any WZW model at
arbitrary level to search systematically for modular invariant physical
partition functions. Our method is based essentially on modding out a known
theory on group manifold by a discrete group .
We apply our method to with , and to
models, and obtain all the known partition functions and some
new ones, and give explicit expressions for all of them.Comment: 30 page ,SUTDP/11/93/72 Department of Physics, Sharif University of
Technolog
Nilpotent Gauging of SL(2,R) models, and Liouville Field
We consider the gauging of WZNW model by its nilpotent subgroup
E(1). The resulting space-time of the corresponding sigma model is seen to
collapse to a one dimensional field theory of Liouville. Gauging the diagonal
subgroup of theory yields an
extremal three dimensional black string. We show that these solutions are
obtained from the two dimensional black hole of Witten and the three
dimensional black string of Horne and Horowitz by boosting the gauge group.Comment: 17 pages, late
Translational-invariant noncommutative gauge theory
A generalized translational invariant noncommutative field theory is analyzed
in detail, and a complete description of translational invariant noncommutative
structures is worked out. The relevant gauge theory is described, and the
planar and nonplanar axial anomalies are obtained.Comment: V1: 23 pages, 4 figures; V2: Section I. improved, References added.
Version accepted for publication in PR
Asymptotic Level State Density for Parabosonic Strings
Making use of some results concerning the theory of partitions, relevant in
number theory, the complete asymptotic behavior, for large , of the level
density of states for a parabosonic string is derived. It is also pointed out
the similarity between parabosonic strings and membranes.Comment: 9 pages , LaTe
Gauge Invariant Cutoff QED
A hidden generalized gauge symmetry of a cutoff QED is used to show the
renormalizability of QED. In particular, it is shown that corresponding Ward
identities are valid all along the renormalization group flow. The exact
Renormalization Group flow equation corresponding to the effective action of a
cutoff lambda phi^4 theory is also derived. Generalization to any gauge group
is indicated.Comment: V1: 18 pages, 2 figures; V2: Discussions improved. Version accepted
for publication in Physica Script
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