Tachyon Condensation and Open String Field theory

TL;DR

This paper studies the process of tachyon condensation in open string field theory, showing how unstable D-branes evolve into stable lower-dimensional D-branes with correct tension through canonical quantization and path-integral methods.

Contribution

It provides a detailed canonical quantization of open strings on unstable D-branes and demonstrates the continuous deformation of string field theory during tachyon condensation.

Findings

Open string propagator derived via path-integral on a stripe.

String field theory deforms continuously during tachyon condensation.

At the infrared fixed point, the unstable D-brane becomes a lower-dimensional D-brane with correct tension.

Abstract

We perform canonical quantization of the open string on a unstable D-brane in the background of the tachyon condensation. Evaluating the Polyakov path-integral on a stripe, we obtain the field theoretical propagator in the open string theory. As the condensation occurs the string field theory is continuously deformed. At the infrared fixed point of the condensation, the open string field on the unstable D-brane transmutes to that on the lower dimensional D-brane with the correct D-brane tension.