Freedman-Townsend vertex from Hamiltonian BRST cohomology

TL;DR

This paper derives the Freedman-Townsend interaction vertex for two-form gauge fields in four dimensions using Hamiltonian BRST cohomology, showing how interactions deform gauge transformations without altering the gauge algebra.

Contribution

It presents a Hamiltonian cohomological method to obtain the Freedman-Townsend vertex, detailing how interactions modify gauge transformations and reducibility relations.

Findings

Derived the Freedman-Townsend interaction from Hamiltonian BRST cohomology.

Showed deformation of gauge transformations and reducibility relations.

Confirmed the gauge algebra remains unchanged.

Abstract

Consistent interactions among a set of two-form gauge fields in four dimensions are derived along a Hamiltonian cohomological procedure. It is shown that the deformation of the BRST charge and BRST-invariant Hamiltonian for the free model leads to the Freedman-Townsend interaction vertex. The resulting interaction deforms both the gauge transformations and reducibility relations, but not the algebra of gauge transformations.