On the Supersymmetry of Non-BPS D-brane

TL;DR

This paper extends boundary string field theory to include target space fermions and nonlinear supersymmetry for non-BPS D-branes, suggesting they belong to a spontaneously broken supersymmetric phase.

Contribution

It introduces a supersymmetric extension of the boundary string field theory action for non-BPS D-branes, incorporating target space fermions and nonlinear supersymmetry.

Findings

Action is nearly uniquely determined up to field redefinitions.

Supports the idea that non-BPS D-branes are in a spontaneously broken supersymmetric phase.

Extends previous models by including target space fermions and supersymmetry.

Abstract

In this paper we extend the boundary string field theory action for a non-BPS D-brane to the one including the target space fermions and the nonlinear supersymmetry with 32 supercharges up to some order. This is based on the idea that the vacuum with a non-BPS D-brane belongs to the spontaneously broken phase of the supersymmetry. As a result, we find that the action is almost uniquely determined up to the field redefinition ambiguities.