Relevant Deformations in Open String Field Theory: a Simple Solution for Lumps

TL;DR

This paper introduces a simple analytic solution in cubic open string field theory that models inhomogeneous tachyon condensation and captures the transition between UV and IR fixed points, including lump solutions.

Contribution

It presents a novel, straightforward solution linking boundary RG flows to open string field configurations, providing explicit lump solutions in both compact and non-compact directions.

Findings

Solution accurately describes IR fixed points of RG flows.

Closed string overlaps reflect shifts in one-point functions.

Examples demonstrate lump solutions in various geometries.

Abstract

We propose a remarkably simple solution of cubic open string field theory which describes inhomogeneous tachyon condensation. The solution is in one-to-one correspondence with the IR fixed point of the RG-flow generated in the two--dimensional world-sheet theory by integrating a relevant operator with mild enough OPE on the boundary. It is shown how the closed string overlap correctly captures the shift in the closed string one point function between the UV and the IR limits of the flow. Examples of lumps in non-compact and compact transverse directions are given.