English

Tachyon Effective Dynamics and de Sitter Vacua

High Energy Physics - Theory 2009-11-10 v2 General Relativity and Quantum Cosmology

Abstract

We show that the DBI action for the singlet sector of the tachyon in two-dimensional string theory has a SL(2,R) symmetry, a real-time counterpart of the ground ring. The action can be rewritten as that of point particles moving in a de Sitter space, whose coordinates are given by the value of the eigenvalue and time. The symmetry then manifests as the isometry group of de Sitter space in two dimensions. We use this fact to write the collective field theory for a large number of branes, which has a natural interpretation as a fermion field in this de Sitter space. After spending some time building geometrical insight on facts about the condensation process, the state corresponding to a sD-brane is identified and standard results in quantum field theory in curved space-time are used to compute the backreaction of the thermal background.

Keywords

Cite

@article{arxiv.hep-th/0403217,
  title  = {Tachyon Effective Dynamics and de Sitter Vacua},
  author = {Bruno Carneiro da Cunha},
  journal= {arXiv preprint arXiv:hep-th/0403217},
  year   = {2009}
}

Comments

28 pages, 1 eps figure. Uses graphicx, setspace. v2:corrected typos, added references, clarified discussion on backreaction

R2 v1 2026-07-22T15:22:33.452Z