Rolling Tachyon with Electric and Magnetic Fields -- T-duality approach -----

TL;DR

This paper investigates the decay of unstable Dp-branes with electric and magnetic fields by constructing boundary states via T-duality, revealing how gauge fields influence closed string couplings and decay dynamics.

Contribution

It introduces a T-duality based method to incorporate electric and magnetic fields into Dp-brane boundary states and compares boundary state results with effective field theory analysis.

Findings

Electric field enhances coupling of closed string modes along its direction.

A simple recipe for turning on gauge fields in boundary states is provided.

The boundary state approach aligns with effective field theory predictions.

Abstract

We study the decay of unstable D$p$-branes when the world-volume gauge field is turned on. We obtain the relevant Dp-brane boundary state with electric and magnetic fields by boosting and rotating the rolling tachyon boundary state of a D(p-1)-brane and then T-dualizing along one of the transverse directions. A simple recipe to turn on the gauge fields in the boundary state is given. We find that the effect of the electric field is to parametrically enhance coupling of closed string oscillation modes along the electric field direction and provide an intuitive understanding of the result in the T-dualized picture. We also analyze the system by using the effective field theory and compare the result with the boundary state approach.