Tachyon Matter

TL;DR

The paper demonstrates that the decay of unstable D-branes results in a pressureless gas with stored energy in open string fields, despite the absence of open string degrees of freedom at the potential minimum.

Contribution

It provides a new understanding of tachyon condensation leading to pressureless gas and offers an effective field theory description of this process.

Findings

Decay produces pressureless gas with non-zero energy density.

Energy remains stored in open string fields even at the potential minimum.

Effective field theory captures the decay process and resulting state.

Abstract

It is shown that classical decay of unstable D-branes in bosonic and superstring theories produces pressureless gas with non-zero energy density. The energy density is stored in the open string fields, even though around the minimum of the tachyon potential there are no open string degrees of freedom. We also give a description of this phenomenon in an effective field theory.