Fermionic Coset Realization of Primaries in Critical Statistical Models

We obtain a fermionic coset realization of the primaries of minimal unitary models and show how their four-point functions may be calculated by the use of a reduction formula. We illustrate the construction for the Ising model, where we obtain an explicit realization of the energy operator, Onsager fermions, as well as of the order and disorder operators realizing the dual algebra, in terms of constrained Dirac fermions. The four-point correlators of these operators are shown to agree with those obtained by other methods.Comment: 26 pages, Latex fil

On the Hamilton-Jacobi equation for second class constrained systems

We discuss a general procedure for arriving at the Hamilton-Jacobi equation of second-class constrained systems, and illustrate it in terms of a number of examples by explicitely obtaining the respective Hamilton principal function, and verifying that it leads to the correct solution to the Euler-Lagrange equations.Comment: 17 pages, to appear in Ann. Phy

BRST Analysis of QCD_2 as a Perturbed WZW Theory

Integrability of Quantum Chromodynamics in 1+1 dimensions has recently been suggested by formulating it as a perturbed conformal Wess-Zumino-Witten Theory. The present paper further elucidates this formulation, by presenting a detailed BRST analysis.Comment: 14 pages, LaTe

Quantization of spontaneously broken gauge theory based on the BFT-BFV Formalism

We quantize the spontaneously broken abelian U(1) Higgs model by using the improved BFT and BFV formalisms. We have constructed the BFT physical fields, and obtain the first class observables including the Hamiltonian in terms of these fields. We have also explicitly shown that there are exact form invariances between the second class and first class quantities. Then, according to the BFV formalism, we have derived the corresponding Lagrangian having U(1) gauge symmetry. We also discuss at the classical level how one easily gets the first class Lagrangian from the symmetry-broken second class Lagrangian.Comment: 16 pages, latex, final version published in Mod. Phys. Lett.

Hilbert Space of Isomorphic Representations of Bosonized Chiral QCD2QCD_2

We analyse the Hilbert space structure of the isomorphic gauge non-invariant and gauge invariant bosonized formulations of chiral $QCD_2$ for the particular case of the Jackiw-Rajaraman parameter $a = 2$. The BRST subsidiary conditions are found not to provide a sufficient criterium for defining physical states in the Hilbert space and additional superselection rules must to be taken into account. We examine the effect of the use of a redundant field algebra in deriving basic properties of the model. We also discuss the constraint structure of the gauge invariant formulation and show that the only primary constraints are of first class.Comment: LaTeX, 19 page

Recursive Construction of Generator for Lagrangian Gauge Symmetries

We obtain, for a subclass of structure functions characterizing a first class Hamiltonian system, recursive relations from which the general form of the local symmetry transformations can be constructed in terms of the independent gauge parameters. We apply this to a non-trivial Hamiltonian system involving two primary constraints, as well as two secondary constraints of the Nambu-Goto type.Comment: 10 pages, Late