Boundary States for D-branes with Traveling Waves

TL;DR

This paper constructs boundary states for D-branes with traveling waves, analyzes their interactions in various compactification scenarios, and explores implications for open string tachyon condensation.

Contribution

It introduces a covariant formalism for boundary states with traveling waves and examines their interactions, including effects of compactification and applications to tachyon condensation.

Findings

Vacuum amplitudes are trivial in non-compact space.

Compactification induces non-trivial time-dependent effects.

Interactions between oppositely traveling waves show non-trivial dynamics.

Abstract

We construct boundary states for D-branes which carry traveling waves in the covariant formalism. We compute their vacuum amplitudes to investigate their interactions. In non-compact space, the vacuum amplitudes become trivial as is common in plane wave geometries. However, we found that if they are compactified in the traveling direction, then the amplitudes are affected by non-trivial time dependent effects. The interaction between D-branes with waves traveling in the opposite directions (`pulse-antipulse scattering') are also computed. Furthermore, we apply these ideas to open string tachyon condensation with traveling waves.