Excited D-brane decay in Cubic String Field Theory and in Bosonic String Theory

TL;DR

This paper compares decay amplitudes of excited D-branes in cubic string field theory and bosonic string theory, showing identical pole structures and consistency with a tachyonic Dirac-Born-Infeld action.

Contribution

It explicitly evaluates decay amplitudes in both theories and demonstrates their equivalence and consistency with effective tachyonic actions.

Findings

Decay amplitudes have identical pole structures in both theories.

Leading contact terms match the tachyonic Dirac-Born-Infeld action.

Results support the effective description of D-brane decay with tachyonic fields.

Abstract

In the cubic string field theory, using the gauge invariant operators corresponding to the on-shell closed string vertex operators, we have explicitly evaluated the decay amplitudes of two open string tachyons or gauge fields to one closed string tachyon or graviton up to level two. We then evaluated the same amplitudes in the bosonic string theory, and shown that the amplitudes in both theories have exactly the same pole structure. We have also expanded the decay amplitudes in the bosonic string theory around the Mandelstam variable s=0, and shown that their leading contact terms are fully consistent with a tachyonic Dirac-Born-Infeld action which includes both open string and closed string tachyon.