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D. Bashkirov

Publications and source records attributed to D. Bashkirov.

12 recordsLinked to original sources
arXiv2007

The KT-BRST complex of a degenerate Lagrangian system

Quantization of a Lagrangian field system essentially depends on its degeneracy and implies its BRST extension defined by sets of non-trivial Noether and higher-stage Noether identities. However, one meets a problem how to select trivial and non-trivial higher-stage Noether identities. We show that, under certain conditions, one can associate to a degenerate Lagrangian L the KT-BRST complex of fields, antifields and ghosts whose boundary and coboundary operators provide all non-trivial Noether identities and gauge symmetries of L. In this case, L can be extended to a proper solution of the master equation.

math-ph↗
arXiv2006

Lagrangian BV quantization and Ward identities

The Ward identities are the relations which the complete Green functions of quantum fields satisfy if an original classical Lagrangian system is degenerate. A generic degenerate Lagrangian system of even and odd fields is considered. It is characterized by a hierarchy of reducible Noether identities and gauge supersymmetries parameterized by antifields and ghosts, respectively. In the framework of the BV quantization procedure, an original degenerate Lagrangian is extended to ghosts and antifields in order to satisfy the master equation. Replacing antifields with gauge fixing terms, one comes to a non-degenerate Lagrangian which is quantized in the framework of perturbed QFT. This Lagrangian possesses a BRST symmetry. The corresponding Ward identities are obtained. They generalize Ward identities in the Yang-Mills gauge theory to a general case of reducible gauge supersymmetries depending on derivatives of fields of any order. A supersymmetric Yang-Mills model is considered.

hep-th↗
arXiv2005

On necessary and sufficient conditions of the BV quantization of a generic Lagrangian field system

We address the problem of extending an original field Lagrangian to ghosts and antifields in order to satisfy the master equation in the framework of the BV quantization of Lagrangian field systems. This extension essentially depends on the degeneracy of an original Lagrangian whose Euler-Lagrange operator generally obeys the Noether identities which need not be independent, but satisfy the first-stage Noether identities, and so on. A generic Lagrangian system of even and odd fields on an arbitrary smooth manifold is examined in the algebraic terms of the Grassmann-graded variational bicomplex. We state the necessary and sufficient condition for the existence of the exact antifield Koszul-tate complex whose boundary operator provides all the Noether and higher-stage Noether identities of an original Lagrangian system. The Noether inverse second theorem that we prove associates to this Koszul-Tate complex the sequence of ghosts whose ascent operator provides the gauge and higher-stage gauge supersymmetries of an original Lagrangian. We show that an original Lagrangian is extended to a solution of the master equation if this ascent operator admits a nilpotent extension and only if it is extended to an operator nilpotent on the shell.

hep-th↗
arXiv2005

The antifield Koszul-Tate complex of reducible Noether identities

A generic degenerate Lagrangian system of even and odd fields is examined in algebraic terms of the Grassmann-graded variational bicomplex. Its Euler-Lagrange operator obeys Noether identities which need not be independent, but satisfy first-stage Noether identities, and so on. We show that, if a certain necessary and sufficient condition holds, one can associate to a degenerate Lagrangian system the exact Koszul-Tate complex with the boundary operator whose nilpotency condition restarts all its Noether and higher-stage Noether identities. This complex provides a sufficient analysis of the degeneracy of a Lagrangian system for the purpose of its BV quantization.

math-ph↗
arXiv2005

Noether's second theorem in a general setting. Reducible gauge theories

We prove Noether's direct and inverse second theorems for Lagrangian systems on fiber bundles in the case of gauge symmetries depending on derivatives of dynamic variables of an arbitrary order. The appropriate notions of reducible gauge symmetries and Noether's identities are formulated, and their equivalence by means of certain intertwining operator is proved.

math.DG↗
arXiv2005

Noether's second theorem for BRST symmetries

We present Noether's second theorem for graded Lagrangian systems of even and odd variables on an arbitrary body manifold X in a general case of BRST symmetries depending on derivatives of dynamic variables and ghosts of any finite order. As a preliminary step, Noether's second theorem for Lagrangian systems on fiber bundles over X possessing gauge symmetries depending on derivatives of dynamic variables and parameters of arbitrary order is proved.

math-ph↗
arXiv2005

On the BV quantization of gauge gravitation theory

Quantization of gravitation theory as gauge theory of general covariant transformations in the framework of Batalin-Vilkoviski (BV) formalism is considered. Its gauge-fixed Lagrangian is constructed.

hep-th↗
arXiv2004

Space-time BRST symmetries

Bearing in mind BV quantization of gauge gravitation theory, we extend general covariant transformations to the BRST ones.

hep-th↗
arXiv2004

BV quantization of covariant (polysymplectic) Hamiltonian field theory

Covariant (polysymplectic)Hamiltonian field theory is the Hamiltonian counterpart of classical Lagrangian field theory. They are quasi-equivalent in the case of almost-regular Lagrangians. This work addresses BV quantization of polysymplectic Hamiltonian field theory. We compare BV quantizations of associated Lagrangian and polysymplectic Hamiltonian field systems in the case of almost-regular quadratic Lagrangians.

hep-th↗
arXiv2004

BV quantization of a generic degenerate quadratic lagrangian

Generalizing the Yang-Mills gauge theory, we provide the BV quantization of a field model with a generic almost-regular quadratic Lagrangian by use of the fact that the configuration space of such a field model is split into the gauge-invariant and gauge-fixing parts.

hep-th↗
arXiv2004

Covariant Hamiltonian field theory. Path integral quantization

The Hamiltonian counterpart of classical Lagrangian field theory is covariant Hamiltonian field theory where momenta correspond to derivatives of fields with respect to all world coordinates. In particular, classical Lagrangian and covariant Hamiltonian field theories are equivalent in the case of a hyperregular Lagrangian, and they are quasi-equivalent if a Lagrangian is almost-regular. In order to quantize covariant Hamiltonian field theory, one usually attempts to construct and quantize a multisymplectic generalization of the Poisson bracket. In the present work, the path integral quantization of covariant Hamiltonian field theory is suggested. We use the fact that a covariant Hamiltonian field system is equivalent to a certain Lagrangian system on a phase space which is quantized in the framework of perturbative field theory. We show that, in the case of almost-regular quadratic Lagrangians, path integral quantizations of associated Lagrangian and Hamiltonian field theories are equivalent.

hep-th↗