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R. Banerjee

Publications and source records attributed to R. Banerjee.

At least 91 records · Page 5Linked to original sources

Bosonisation and Soldering of Dual Symmetries in Two and Three Dimensions

We develop a technique that solders the dual aspects of some symmetry following from the bosonisation of two distinct fermionic models, thereby leading to new results which cannot be otherwise obtained. Exploiting this technique, the two dimensional chiral determinants with opposite chirality are soldered to reproduce either the usual gauge invariant expression leading to the Schwinger model or, alternatively, the Thirring model. Likewise, two apparently independent three dimensional massive Thirring models with same coupling but opposite mass signatures, in the long wavelegth limit, combine by the process of bosonisation and soldering to yield an effective massive Maxwell theory. The current bosonisation formulas are given, both in the original independent formulation as well as the effective theory, and shown to yield consistent results for the correlation functions. Similar features also hold for quantum electrodynamics in three dimensions.

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Bose Symmetry and Chiral Decomposition of 2D Fermionic Determinants

We show in a precise way, either in the fermionic or its bosonized version, that Bose symmetry provides a systematic way to carry out the chiral decomposition of the two dimensional fermionic determinant. Interpreted properly, we show that there is no obstruction of this decomposition to gauge invariance, as is usually claimed. Finally, a new way of interpreting the Polyakov-Wiegman identity is proposed.

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Duality Symmetry and Soldering in Different Dimensions

We develop a systematic method of obtaining duality symmetric actions in different dimensions. This technique is applied for the quantum mechanical harmonic oscillator, the scalar field theory in two dimensions and the Maxwell theory in four dimensions. In all cases there are two such distinct actions. Furthermore, by soldering these distinct actions in any dimension a master action is obtained which is duality invariant under a much bigger set of symmetries than is usually envisaged. The concept of swapping duality is introduced and its implications are discussed. The effects of coupling to gravity are also elaborated. Finally, the extension of the analysis for arbitrary dimensions is indicated.

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A New Approach for Bosonization of Massive Thirring Model in Three Dimensions

We develop a new approach for bosonization based on the direct comparison of current correlation functions and apply it to the case of the Massive Thirring Model in three dimensions in the weak coupling regime, but with an arbitrary mass. Explicit bosonized forms for the lagrangian and the current are obtained in terms of a vector gauge field. Exact results for the corresponding expressions are also obtained in the case of a free massive fermion. Finally, a comment on the derivation of the current algebra directly from the bosonized expressions is included.

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Different Approaches for Bosonization in Higher Dimensions

We describe two distinct approaches for bosonization in higher dimensions; one is based on a direct comparison of current correlation functions while the other relies on a Master lagrangean formalism. These are used to bosonise the Massive Thirring Model in three and four dimensions in the weak coupling regime but with an arbitrary fermion mass. In both approaches the explicit bosonised lagrangean and current are derived in terms of gauge fields. The complete equivalence of the two bosonization methods is established. Exact results for the free massive fermion theory are also obtained. Finally, the two-dimensional theory is revisited and the possibility of extending this analysis for arbitrary dimensions is indicated.

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Hamiltonian embedding of the massive Yang-Mills theory and the generalized Stückelberg formalism

Using the general notions of Batalin, Fradkin, Fradkina and Tyutin to convert second class systems into first class ones, we present a gauge invariant formulation of the massive Yang-Mills theory by embedding it in an extended phase space. The infinite set of correction terms necessary for obtaining the involutive constraints and Hamiltonian is explicitly computed and expressed in a closed form. It is also shown that the extra fields introduced in the correction terms are exactly identified with the auxiliary scalars used in the generalized Stückelberg formalism for converting a gauge noninvariant Lagrangian into a gauge invariant form.

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Gauge Independent Reduction of a Solvable Model with Gribov-Like Ambiguity

We present a gauge independent Lagrangian method of abstracting the reduced space of a solvable model with Gribov-like ambiguity, recently proposed by Friedberg, Lee, Pang and Ren. The reduced space is found to agree with the explicit solutions obtained by these authors. Complications related to gauge fixing are analysed. The Gribov ambiguity manifests by a nonuniqueness in the canonical transformations mapping the hamiltonian in the afflicted gauge with that obtained gauge independently. The operator ordering problem in this gauge is investigated and a prescription is suggested so that the results coincide with the usual hamiltonian formalism using the Schrödinger representation. Finally, a Dirac analysis of the model is elaborated. In this treatment it is shown how the existence of a nontrivial canonical set in the ambiguity-ridden gauge yields the connection with the previous hamiltonian formalism.

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Non abelian bosonisation in three dimensional field theory

We develop a method based on the generalised Stückelberg prescription for discussing bosonisation in the low energy regime of the SU(2) massive Thirring model in 2+1 dimensions. For arbitrary values of the coupling parameter the bosonised theory is found to be a nonabelian gauge theory whose physical sector is explicitly obtained. In the case of vanishing coupling this gauge theory can be identified with the SU(2) Yang-Mills Chern-Simons theory in the limit when the Yang-Mills term vanishes. Bosonisation identities for the fermionic current are derived.

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Explicit Bosonization of the Massive Thirring Model in 3+1 Dimensions

We bosonize the Massive Thirring Model in 3+1D for small coupling constant and arbitrary mass. The bosonized action is explicitly obtained both in terms of a Kalb-Ramond tensor field as well as in terms of a dual vector field. An exact bosonization formula for the current is derived. The small and large mass limits of the bosonized theory are examined in both the direct and dual forms. We finally obtain the exact bosonization of the free fermion with an arbitrary mass.

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Galilean symmetry in a nonabelian Chern Simons matter system

We study the Galilean symmetry in a nonrelativistic model, recently advanced by Bak, Jackiw and Pi, involving the coupling of a nonabelian Chern-Simons term with matter fields. The validity of the Galilean algebra on the constraint surface is demonstrated in the gauge independent formalism. Then the reduced space formulation is discussed in the axial gauge using the symplectic method. An anomalous term in the Galilean algebra is obtained which can be eliminated by demanding conditions on the Green function. Finally, the axial gauge is also treated by Dirac's method. Galilean symmetry is preserved in this method. Comparisions with the symplectic approach reveal some interesting features.

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Spin of Chern-Simons vortices

We discuss a novel method of obtaining the fractional spin of abelian and nonabelian Chern-Simons vortices. This spin is interpreted as the difference between the angular momentum obtained by modifying Schwinger's energy momentum tensor by the Gauss constraint, and the canonical (Noether) angular momentum. It is found to be a boundary term depending only on the gauge field and, hence, is independent of the matter sector to which the Chern-Simons term couples. Addition of the Maxwell term does not alter the fractional spin.

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Generalised Hamiltonian embedding of the Proca model

We convert the second class Proca model into a first class theory by using the generalised prescription of Batalin, Fradkin and Tyutin. We then show how a basic set of gauge invariant fields in the embedded model can be identified with the fundamental fields in the proca model as well as with the observables in the Stückelberg model or in the model involving the interaction of an abelian 2-form field with the Maxwell field. The connection of these models with the massive Kalb-Ramond model is also elucidated within a path integral approach.

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Duality and Bosonisation in Arbitrary Dimensions

A functional integral approach is developed to discuss the bosonisation of the massive Thirring and the massive Schwinger models in arbitrary D-dimensions. It is found that these models, to {\it all} orders in the inverse fermi mass, bosonise to a theory involving a usual gauge field and a (D-2) rank antisymmetric (Kalb-Ramond) tensor field. Explicit bosonisation identities for the fermion current are deduced. Specialising to the lowest order reveals (for any $D \geq 4$) a mapping between the massive Thirring model and the Proca model. It also establishes an exact duality between the Proca model and the massive (D-2) rank Kalb-Ramond model. Schwinger terms in the current algebra are computed. Conventional bosonisation results in D=2, 3 are reproduced.

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Bosonisation in Three-Dimensional Quantum Field Theory

We show in three dimensions, using functional integral techniques, the equivalence between the partition functions of the massive Thirring model and a gauge theory with two gauge fields, to all orders in the inverse fermion mass. Detailed bosonisation identities, also valid to all orders in the inverse mass, are derived. Specialisation to the lowest (and next to lowest) orders reveals that the gauge theory simplifies to the Maxwell-Chern-Simons theory. Some interesting consequences are discussed in this case.

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BATALIN-FRADKIN-TYUTIN EMBEDDING OF A SELF-DUAL MODEL AND THE MAXWELL-CHERN-SIMONS THEORY

We convert the self-dual model of Townsend, Pilch, and Nieuwenhuizen to a first-class system using the generalized canonical formalism of Batalin, Fradkin, and Tyutin and show that gauge-invariant fields in the embedded model can be identified with observables in the Maxwell-Chern-Simons theory as well as with the fundamental fields of the self-dual model. We construct the phase-space partition function of the embedded model and demonstrate how a basic set of gauge-variant fields can play the role of either the vector potentials in the Maxwell-Chern-Simons theory or the fundamental fields of the self-dual model by appropriate choices of gauge.

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