Tachyon field theory description of (thermo)dynamics in dS space

Abstract

In this work, we present a few pieces of evidence in support of a possible connection of the gravitational theory in dS space to the worldvolume theory of unstable D-branes. We show that the action describing the geodesic motion of a massive particle (or point-like object) in static dS space turns out to be the same as that of the tachyon field theory for an unstable particle. The motion along the radial direction from the origin, a locally Minkowski spacetime, to the horizon, a locally Rindler space times a sphere, represents just the tachyon condensation process, therefore providing a geometric picture of tachyon condensation. We further study a scalar in global or flat dS and the tachyon fluctuations in a homogeneous tachyon background, representing either the full or half S-brane, on unstable D-branes and find that certain dynamics of the dS universe corresponds to that of the homogeneous full or half S-brane. The thermal temperature of tachyon radiation is found to agree with that felt by any timelike observer in dS space. In string theory context, this temperature is just the Hagedorn one, signaling a phase transition to closed strings. An understanding of this transition in the bulk dS space is also given.Comment: 25 pages, minor corrections, two references adde

Towards the merger of Hawking radiating black holes

“…The result is quite different from that in classical theory, but is similar to the speculations in the Rindler/Tachyon correlation proposed in our previous works [22,23] (and its extension to the dS space [24]). The mysterious similarity between the action of a probe particle in Rindler space (the geometry near the horizon of a non-extreme black hole) and the tachyon effective action may suggest that the collapsing process of matter towards a black hole horizon is a tachyon condensation process, with the Hawking temperature equal to the Hagedorn temperature in tachyon field theory.…”

Black hole entropy from tachyon condensation

“…It is easy to find that the Hagedorn temperature in this tachyon action is equal to the Hawking temperature (6) of the black hole [9,17]:…”