Corrections to D-brane Action and Generalized Boundary State

TL;DR

This paper extends the boundary state formalism in bosonic string theory to include non-constant gauge fields, deriving derivative corrections to the D-brane action and ensuring BRST invariance.

Contribution

It introduces a generalized boundary state with non-constant gauge fields, satisfying nonlinear boundary conditions and BRST invariance, and derives derivative corrections to the D-brane action.

Findings

Generalized boundary state with non-constant gauge fields constructed.

Divergences match those from string sigma model calculations.

Partial derivative corrections to D-brane action obtained.

Abstract

In this paper, we generalize a boundary state to the one incorporating non-constant gauge field strength as an external background coupled to the boundary of a string worldsheet in bosonic string theory. This newly defined boundary state satisfies generalized nonlinear boundary conditions with non-constant gauge field strength, and is BRST invariant. The divergence immanent in this boundary state coincide with the one calculated in a string sigma model. We extract the relevant massless part of this generalized boundary state, and give a part of the D-brane action with the non-constant gauge field strength, that is, derivative corrections to the D-brane action.