On the Calculation of Effective Actions by String Methods

TL;DR

This paper revisits the string-derived Bern-Kosower formalism to compute effective actions and form factors, comparing results with heat kernel methods and proposing a covariant calculation scheme for gauge theories.

Contribution

It introduces a covariant calculational scheme for one-loop effective actions and compares form factors derived from string methods with heat kernel approaches.

Findings

Calculated two- and three-point form factors in nonabelian effective action.

Compared string-derived form factors with heat kernel results.

Proposed a manifestly covariant scheme for gauge theory effective actions.

Abstract

Strassler's formulation of the string-derived Bern-Kosower formalism is reconsidered with particular emphasis on effective actions and form factors. Two- and three point form factors in the nonabelian effective action are calculated and compared with those obtained in the heat kernel approach of Barvinsky, Vilkovisky et al. We discuss the Fock-Schwinger gauge and propose a manifestly covariant calculational scheme for one-loop effective actions in gauge theory.