One-loop Correction of the Tachyon Action in Boundary Superstring Field Theory

TL;DR

This paper calculates the one-loop correction to the tachyon action in boundary superstring field theory for unstable D-branes, revealing how quantum effects modify the classical tachyon dynamics.

Contribution

It introduces a method to compute one-loop corrections using the annulus partition function, linking the genus expansion to an effective string coupling dependent on the tachyon.

Findings

One-loop correction is derived from the annulus partition function.

The effective string coupling is expressed as g_s exp(-T^2/4).

Genus expansion is governed by this effective coupling.

Abstract

We compute one-loop correction to the string field theory action of the tachyon for unstable D-branes in the framework of the boundary superstring field theory. We would expect that the one-loop correction comes from the partition function of the two-dimensional world-sheet theory on the annulus. The annulus correction suggests that the genus expansion is, somehow, governed by the effective string coupling defined in terms of the tachyon \lambda=g_s exp(-T^2/4).