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

Abstract

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.