Tachyon condensation in unbalanced D-anti D system

TL;DR

This paper investigates tachyon condensation in asymmetric D-brane systems within type IIB superstring theory, demonstrating the emergence of BPS D1-branes and analyzing their interactions with background D5-branes.

Contribution

It provides a detailed analysis of tachyon condensation in unbalanced D-anti D systems, revealing the formation of BPS D1-branes and their force interactions in a large N D5-brane background.

Findings

A BPS D1-brane emerges after condensation in a D5-anti D5 system.

The resultant D1-brane experiences no force from background D5-branes.

In a single D5-anti D5 pair, the resulting D3-brane is attracted to the background D5-branes.

Abstract

The tachyon condensation is studied in asymmetric D-anti D systems. Taking a system of two pairs of D5-anti D5 in type IIB superstring theory in the background of large N D5-branes, we show that one BPS D1-brane comes out after the condensation. It is also seen that the BPS D1-brane feels no force from the background D5-branes. We also show that the inclusion of the fluctuation fields gives an expected Dirac-Born-Infeld (DBI) action of the resultant D1-brane. On the other hand, in the case of one pair of D5-anti D5 in the same background, we show that the resultant BPS D3-brane experiences attractive force from the background D5-branes.