Tachyon Condensation, Boundary State and Noncommutative Solitons

TL;DR

This paper explores tachyon condensation on unstable D-branes using boundary state formulation, demonstrating how these branes evolve into lower-dimensional branes and clarifying the link between commutative and noncommutative descriptions.

Contribution

It explicitly constructs boundary states during tachyon condensation with NS B-field and compares commutative and noncommutative frameworks.

Findings

Unstable D-branes behave as extended objects during condensation.

D-branes reduce to lower-dimensional branes at the infrared fixed point.

The relationship between commutative and noncommutative descriptions is clarified.

Abstract

We discuss the tachyon condensation in a single unstable D-brane in the framework of boundary state formulation. The boundary state in the background of the tachyon condensation and the NS B-field is explicitly constructed. We show in both commutative theory and noncommutative theory that the unstable D-branes behaves like an extended object and eventually reduces to the lower dimensional D-branes as the system approaches the infrared fixed point. We clarify the relationship between the commutative field theoretical description of the tachyon condensation and the noncommutative one.