Tachyon condensation in boundary string field theory at one loop

TL;DR

This paper calculates the one-loop partition function for quadratic tachyon backgrounds in open string theory, analyzing divergences, decay rates, and corrections to tachyon condensation and brane tensions.

Contribution

It provides a detailed one-loop analysis of tachyon condensation in boundary string field theory, including divergences, decay rates, and corrections to brane tensions.

Findings

Computed the one-loop partition function in open string theory with tachyon background.

Analyzed divergences and decay rates via analytic continuation.

Studied one-loop corrections to tachyon potential and brane tensions.

Abstract

We compute the one-loop partition function for quadratic tachyon background in open string theory. Both closed and open string representations are developed. Using these representations we study the one-loop divergences in the partition function in the presence of the tachyon background. The divergences due to the open and closed string tachyons are treated by analytic continuation in the tachyon mass squared. We pay particular attention to the imaginary part of the analytically continued expressions. The last one gives the decay rate of the unstable vacuum. The dilaton tadpole is also given some partial consideration. The partition function is further used to study corrections to tachyon condensation processes describing brane descent relations. Assuming the boundary string field theory prescription for construction of the string field action via partition function holds at one loop level we study the one-loop corrections to the tachyon potential and to the tensions of lower-dimensional branes.