Tachyon condensation and `bounce' in the D1-D5 system

TL;DR

This paper constructs supergravity solutions for D1-D3-D5 microstates with B field moduli, analyzing the infall and bounce of a D1 brane, and relates these to tachyon condensation behavior in the dual field theory.

Contribution

It provides explicit supergravity solutions for D1-D3-D5 microstates with B field moduli and studies the dynamics of a probe D1 brane, revealing bounce behavior linked to tachyon condensation.

Findings

D1 brane bounces off the smooth end of the geometry.

The bounce depends on microstate and approach direction.

Tachyon mode condenses but bounces back without deep condensation.

Abstract

We construct supergravity solutions dual to microstates of the D1-D3-D5 system with nonzero B field moduli. Just like the D1-D5 solutions in hep-th/0109154 these solutions are generically nonsingular everywhere, with the `throat' closing smoothly near r=0. We write expressions relating the asymptotic supergravity fields to the integral brane charges. We study the infall of a D1 brane down the throat of the geometries. This test brane `bounces' off the smooth end for generic initial conditions. The details of the bounce depend on both the choice of D1-D3-D5 microstate and the direction of approach of the infalling D1 brane. In the dual field theory description we see that the tachyon mode starts to condense, but the tachyon bounces back up the potential hill without reaching the deepest point of the potential.