Closed-string Tachyon Condensation and Loop Corrected On-shell Effective Action of Open-String Tachyons

摘要

We propose a basic strategy to obtain a consistent on-shell effective action of open-string tachyons, on the background where closed-string tachyons are already condensed. We use sigma-modal approach, basically. We regard D-instanton-like objects with appropriate weight as closed-string tachyon tadpoles, and we insert them into worldsheets to analyze the effect of closed-string tachyons.