English

(A)symmetric Tachyon Rolling in de Sitter Spacetime: A universe devoid of Planck density

High Energy Physics - Theory 2010-04-05 v3 Astrophysics

Abstract

In a recent paper we studied rolling tachyon flat FRW cosmologies, but those admitting only time-reversal asymmetric boundary conditions. The time-reversal symmetric cosmologies have been studied by Sen previously. We show explicitly here that through appropriate choice of initial conditions, the time evolution of the Hubble parameter in these two types of solutions can be made completely identical for t>0t>0, except near t=0t=0. The rolling tachyon solution also gives rise to necessary inflation. We find that universe does start as a string size object (with string scale 1015GeV10^{15} GeV) with a string mass density 1078gm.cm3\simeq 10^{78} gm. cm^{-3} and not with Planck density.

Keywords

Cite

@article{arxiv.hep-th/0508101,
  title  = {(A)symmetric Tachyon Rolling in de Sitter Spacetime: A universe devoid of Planck density},
  author = {Harvendra Singh},
  journal= {arXiv preprint arXiv:hep-th/0508101},
  year   = {2010}
}

Comments

17 pages, 5 figures; V2 major change in sec-4 & references added; V3 sec-4 is further enlarged (more figures)