Generalized Supersymetric Boundary State

TL;DR

This paper extends the supersymmetric boundary state to include arbitrary gauge fields, ensuring BRST invariance and linking divergence cancellation to the superstring sigma model's beta function, with implications for D-brane dynamics.

Contribution

It introduces a generalized boundary state incorporating non-constant gauge fields and scalar configurations, maintaining BRST invariance and connecting divergences to the superstring sigma model.

Findings

Boundary state includes arbitrary gauge field configurations.

Vanishing beta function corresponds to divergence-free boundary state.

Derivative corrections to D-brane action vanish up to first order.

Abstract

Following our previous paper (hep-th/9909027), we generalize a supersymmetric boundary state so that arbitrary configuration of the gauge field coupled to the boundary of the worldsheet is incorpolated. This generalized boundary state is BRST invariant and satisfy the non-linear boundary conditions with non-constant gauge field strength. This boundary state contains divergence which is identical with the loop divergence in a superstring sigma model. Hence vanishing of the beta function in the superstring sigma model corresponds to a well-defined boundary state with no divergence. The coupling of a single closed superstring massless mode with multiple open string massless modes is encoded in the boundary state, and we confirm that derivative correction to the D-brane action in this sector vanishes up to the first non-trivial order O(alpha'(derivative)^2). Combining T-dualities, we incorpolate also general configurations of the scalar fields on the D-brane, and construct boundary states representing branes stuck to another D-brane, with use of BIon configuration.