S-brane Actions

TL;DR

This paper derives effective Dirac-Born-Infeld actions for S-branes, models their role in fundamental string formation during tachyon condensation, and demonstrates spike solutions representing string production.

Contribution

It introduces a new effective action for S-branes in time-dependent tachyon backgrounds and links spike solutions to fundamental string formation.

Findings

S-brane action is a DBI action with gauge and scalar fields.

Spike solutions correspond to confined electric flux tubes.

Fundamental strings are produced during tachyon rolling.

Abstract

We derive effective actions for Spacelike branes (S-branes) and find a solution describing the formation of fundamental strings in the rolling tachyon background. The S-brane action is a Dirac-Born-Infeld action for Euclidean worldvolumes defined in the context of time-dependent tachyon condensation of non-BPS branes. It includes gauge fields and in particular a scalar field associated with translation along the time direction. We show that the BIon spike solutions constructed in this system correspond to the production of a confined electric flux tube (a fundamental string) at late time of the rolling tachyon.