arXiv subjects

I. L. Buchbinder

Publications and source records attributed to I. L. Buchbinder.

At least 127 records · Page 7Linked to original sources

arXiv2009

ABJM models in N=3 harmonic superspace

We construct the classical action of the Aharony-Bergman-Jafferis-Maldacena (ABJM) model in the N=3, d=3 harmonic superspace. In such a formulation three out of six supersymmetries are realized off shell while the other three mix the superfields and close on shell. The superfield action involves two hypermultiplet superfields in the bifundamental representation of the gauge group and two Chern-Simons gauge superfields corresponding to the left and right gauge groups. The N=3 superconformal invariance allows only for a minimal gauge interaction of the hypermultiplets. Amazingly, the correct sextic scalar potential of ABJM emerges after the elimination of auxiliary fields. Besides the original U(N)xU(N) ABJM model, we also construct N=3 superfield formulations of some generalizations. For the SU(2)xSU(2) case we give a simple superfield proof of its enhanced N=8 supersymmetry and SO(8) R-symmetry.

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arXiv2009

Lagrangian formulation of massive fermionic totally antisymmetric tensor field theory in AdS_d space

We apply the BRST approach, developed for higher spin field theories, to Lagrangian construction for totally antisymmetric massive fermionic fields in AdS_d space. As well as generic higher spin massive theories, the obtained Lagrangian theory is a reducible gauge model containing, besides the basic field, a number of auxiliary (Stuckelberg) fields and the order of reducibility grows with the value of the rank of the antisymmetric field. However, unlike the generic higher spin theory, for the special case under consideration we show that one can get rid of all the auxiliary fields and the final Lagrangian for fermionic antisymmetric field is formulated only in terms of basic field.

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arXiv2008

Quartet unconstrained formulation for massive higher spin fields

We generalize the unconstrained description of free massless higher spin fields previously developed in [Nucl.Phys. B 779 (2007) 155] to the case of free massive higher spin fields in a flat space of arbitrary dimension. The Lagrangian is given in an easy-to-handle form for an arbitrary value of spin. It is local, free from higher derivative terms, and involves a minimal number of auxiliary fields needed for an unconstrained gauge invariant description of a free massive higher spin field in arbitrary dimension.

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arXiv2008

BRST approach to Lagrangian formulation of bosonic totally antisymmeric tensor fields in curved space

We apply the BRST approach, previously developed for higher spin field theories, to gauge invariant Lagrangian construction for antisymmetric massive and massless bosonic fields in arbitrary d-dimensional curved space. The obtained theories are reducible gauge models both in massless and massive cases and the order of reducibility grows with the value of the rank of the antisymmetric field. In both the cases the Lagrangians contain the sets of auxiliary fields and possess more rich gauge symmetry in comparison with standard Lagrangian formulation for the antisymmetric fields. This serves additional demonstration of universality of the BRST approach for Lagrangian constructions in various field models.

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arXiv2008

One-loop effective action in ${\cal N}=2$ supersymmetric massive Yang-Mills theory

We consider the ${\cal N}=2$ supersymmetric theory of the massive Yang-Mills field formulated in the ${\cal N}=2$ harmonic superspace. The various gauge-invariant forms of writing the mass term in the action (in particular, using the Stueckelberg superfield), which result in dual formulations of the theory, are presented. We develop a gauge-invariant and explicitly supersymmetric scheme of the loop off-shell expansion of the superfield effective action. In the framework of this scheme, we calculate gauge-invariant and explicitly ${\cal N}=2$ supersymmetric one-loop counterterms including new counterterms depending on the Stueckelberg superfield. Component structure of one of these counterterms is analyzed.

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arXiv2008

Quantum Equivalence of Massive Antisymmetric Tensor Field Models in Curved Space

We study the effective actions for massive rank-2 and rank-3 antisymmetric tensor field models in curved space-time. These models are classically equivalent to massive vector field and massive scalar field with minimal coupling to gravity respectively. We prove that effective action for massive rank-2 antisymmetric tensor field is exactly equal to one for massive vector field and effective action for massive rank-3 antisymmetric tensor field is exactly equal to one for massive scalar field. Prove is based on an identity for mass-dependent zeta-functions associated with Laplacians acting on $p$-forms.

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arXiv2008

N=3 Superparticle Model

We consider the formulation and quantization of the N=3 superparticle model, both with and without central charge. Without the central charge the action possesses U(3) invariance and therefore is naturally quantized in the N=3 harmonic superspace. The quantization reproduces the N=3 supergauge strength multiplets, described by analytic N=3 superfields and a gravitino multiplet as a constrained N=3 chiral superfield. When the central charge is present, it breaks the U(3) R-symmetry of N=3 superalgebra down to SU(2)xU(1), and the corresponding superparticle model is formulated in the N=2 harmonic superspace extended by a pair of extra Grassmann variables. The quantization of such a model leads to the massive BPS N=3 vector multiplet. It is shown that upon additional superfield constraints such multiplet reduces to the massive N=2 vector multiplet.

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arXiv2008

N=4 superparticle and super Yang-Mills theory in USp(4) harmonic superspace

We study the N=4 harmonic superparticle model, both with and without central charge and quantize it. Since the central charge breaks the U(4) R-symmetry group of the N=4 superalgebra down to USp(4), we consider the superparticle dynamics in N=4 harmonic superspace with USp(4)/(U(1)xU(1)) harmonic variables. We show that the quantization of a massive superparticle with central charge leads to a superfield realization of the N=4 massive vector multiplet in N=4 harmonic superspace. In the massless case without central charge the superparticle quantization reproduces three different multiplets: the N=4 SYM multiplet, the N=4 gravitino multiplet and N=4 supergravity multiplet. The SYM multiplet is described by six analytic superfield strengths with different types of analyticity. We show that these strengths solve the N=4 SYM constraints and can be used for the construction of actions in N=4 harmonic superspace.

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arXiv2008

BRST charge for nonlinear algebras

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arXiv2007

Progress in Gauge Invariant Lagrangian Construction for Massive Higher Spin Fields

We review the recently developed general gauge invariant approach to Lagrangian construction for massive higher spin fields in Minkowski and AdS spaces of arbitrary dimension. Higher spin Lagrangian, describing the dynamics of the fields with any spin, is formulated with help of BRST-BFV operator in auxiliary Fock space. No off-shell constraints on the fields and gauge parameters are imposed. The construction is also applied to tensor higher spin fields with index symmetry corresponding to a multirow Young tableau.

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arXiv2007

Gauge theory in deformed N=(1,1) superspace

We review the non-anticommutative Q-deformations of N=(1,1) supersymmetric theories in four-dimensional Euclidean harmonic superspace. These deformations preserve chirality and harmonic Grassmann analyticity. The associated field theories arise as a low-energy limit of string theory in specific backgrounds and generalize the Moyal-deformed supersymmetric field theories. A characteristic feature of the Q-deformed theories is the half-breaking of supersymmetry in the chiral sector of the Euclidean superspace. Our main focus is on the chiral singlet Q-deformation, which is distinguished by preserving the SO(4) Spin(4) ``Lorentz'' symmetry and the SU(2) R-symmetry. We present the superfield and component structures of the deformed N=(1,0) supersymmetric gauge theory as well as of hypermultiplets coupled to a gauge superfield: invariant actions, deformed transformation rules, and so on. We discuss quantum aspects of these models and prove their renormalizability in the abelian case. For the charged hypermultiplet in an abelian gauge superfield background we construct the deformed holomorphic effective action.

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arXiv2007

Gauge invariant Lagrangian construction for massive bosonic mixed symmetry higher spin fields

We develop the BRST approach to gauge invariant Lagrangian construction for the massive mixed symmetry integer higher spin fields described by the rank-two Young tableaux in arbitrary dimensional Minkowski space. The theory is formulated in terms of auxiliary Fock space. No off-shell constraints on the fields and the gauge parameters are imposed. The approach under consideration automatically leads to a gauge invariant Lagrangian for massive theory with all appropriate Stuckelberg fields. It is shown that all the restrictions defining an irreducible representation of the Poincare group arise from Lagrangian formulation as a consequence of the equations of motion and gauge transformations. As an example of the general procedure, we derive the gauge-invariant Lagrangian for massive rank-2 antisymmetric tensor field containing the complete set of auxiliary fields and gauge parameters.

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arXiv2007

Classical BRST charge for nonlinear algebras

We study the construction of the classical nilpotent canonical BRST charge for the nonlinear gauge algebras where a commutator (in terms of Poisson brackets) of the constraints is a finite order polynomial of the constraints. Such a polynomial is characterized by the coefficients forming a set of higher order structure constraints. Assuming the set of constraints to be linearly independent, we find the restrictions on the structure constraints when the nilpotent BRST charge can be written in a simple and universal form. In the case of quadratically nonlinear algebras we find the expression for third order contribution in the ghost fields to the BRST charge without the use of any additional restrictions on the structure constants.

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arXiv2007

Quartet unconstrained formulation for massless higher spin fields

We construct simple unconstrained Lagrangian formulations for massless higher spin fields in flat space of arbitrary dimension and on anti de Sitter background. Starting from the triplet equations of Francia and Sagnotti, which describe a chain of spin modes, we introduce an auxiliary field and find appropriate gauge invariant constraints that single out the spin-s mode. The resulting quartet of fields, thus describing an irreducible representation of the Poincare group, is used to construct simple Lagrangian formulations, which are local, free from higher derivative terms and use equal number of auxiliary fields for an unconstrained description of any value of spin. Our method proves to be most efficient for an unconstrained description of massless higher spin fermions in anti de Sitter space. A relation of the minimal models with the universal BRST approach is discussed.

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arXiv2007

BRST approach to Lagrangian construction for fermionic higher spin fields in AdS space

We develop a general gauge invariant Lagrangian construction for half-integer higher spin fields in the AdS space of any dimension. Starting with formulation in terms of auxiliary Fock space we derive the closed nonlinear symmetry algebras of higher spin fermionic fields in the AdS space and find the corresponding BRST operator. A universal procedure of constructing the gauge invariant Lagrangians describing the dynamics of fermionic fields of any spin is developed. No off-shell constraints for the fields and gauge parameters are imposed from the very beginning. It is shown that all the constraints determining the irreducible representation of the AdS group arise as a consequence of the equations of motion and gauge transformations. As an example of the general procedure, we derive the gauge invariant Lagrangians for massive fermionic fields of spin 1/2 and 3/2 containing the total set of auxiliary fields and gauge symmetries.

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arXiv2007

Quantum Effects in Softly Broken Gauge Theories in Curved Space-Times

The soft breaking of gauge or other symmetries is the typical Quantum Field Theory phenomenon. In many cases one can apply the St$\ddot{\rm u}$ckelberg procedure, which means introducing some additional field or fields and restore the gauge symmetry. The original softly broken theory corresponds to a particular choice of the gauge fixing condition. In this paper we use this scheme for performing quantum calculations for some softly broken gauge theories in an arbitrary curved space-time. The following examples are treated in details: Proca field, massive QED and massive torsion coupled to fermion. Furthermore we present a qualitative discussions of the discontinuity of quantum effects in the massive spin-2 field theory, paying special attention to the similarity and differences with the massless limit in the spin-1 case.

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arXiv2006

Constructing the Cubic Interaction Vertex of Higher Spin Gauge Fields

We propose a method of construction of a cubic interaction in massless Higher Spin gauge theory both in flat and in AdS space-times of arbitrary dimensions. We consider a triplet formulation of the Higher Spin gauge theory and generalize the Higher Spin symmetry algebra of the free model to the corresponding algebra for the case of cubic interaction. The generators of this new algebra carry indexes which label the three Higher Spin fields involved into the cubic interaction. The method is based on the use of oscillator formalism and on the Becchi-Rouet-Stora-Tyutin (BRST) technique. We derive general conditions on the form of cubic interaction vertex and discuss the ambiguities of the vertex which result from field redefinitions. This method can in principle be applied for constructing the Higher Spin interaction vertex at any order. Our results are a first step towards the construction of a Lagrangian for interacting Higher Spin gauge fields that can be holographically studied.

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arXiv2006

Vector-multiplet effective action in the non-anticommutative charged hypermultiplet model

We investigate the quantum aspects of a charged hypermultiplet in deformed N=(1,1) superspace with singlet non-anticommutative deformation of supersymmetry. This model is a "star" modification of the hypermultiplet interacting with a background Abelian vector superfield. We prove that this model is renormalizable in the sense that the divergent part of the effective action is proportional to the N=(1,0) non-anticommutative super Yang-Mills action. We also calculate the finite part of the low-energy effective action depending on the vector multiplet, which corresponds to the (anti)holomorphic potential. The holomorphic piece is just deformed to the star-generalization of the standard holomorphic potential, while the antiholomorphic piece is not. We also reveal the component structure and find the deformation of the mass and the central charge.

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