1126-6708_2009_06_050.pdf (340.49 kB)
Download fileInhomogeneous tachyon condensation
journal contribution
posted on 2023-06-07, 20:50 authored by Mark HindmarshMark Hindmarsh, Huiquan LiWe investigate the spacetime-dependent condensation of the tachyon in effective field theories. Previous work identified singularities in the field which appear in finite time: infinite gradients at the kinks, and (in the eikonal approximation) caustics near local minima. By performing a perturbation analysis, and with numerical simulations, we demonstrate and explain key features of the condensation process: perturbations generically freeze, and minima develop singular second derivatives in finite time (caustics). This last feature has previously been understood in terms of the eikonal approximation to the dynamics. We show explicitly from the field equations how this approximation emerges, and how the caustics develop, both in the DBI and BSFT effective actions. We also investigate the equation of state parameter of tachyon matter showing that it is small, but generically non-zero. The energy density tends to infinity near field minima with a charateristic profile. A proposal to regulate infinities by modifying the effective action is also studied. We find that although the infinities at the kinks are successfully regularised in the time-dependent case, caustics still present.
History
Publication status
- Published
File Version
- Published version
Journal
Journal of High Energy PhysicsISSN
1029-8479Publisher
Springer VerlagExternal DOI
Issue
6Department affiliated with
- Physics and Astronomy Publications
Notes
Article Number: 050Full text available
- Yes
Peer reviewed?
- Yes