AdS/CFT Correspondence and the Reheating of the Brane-Universe

Abstract

We present a mechanism for exit from inflation and reheating using the AdS/CFT correspondence. A cosmological evolution is induced on a probe D3-brane as it moves in a black D-brane background of type-0 string theory. If the tachyon field is non zero, inflation is induced on the brane-universe, with the equation of state parameter in the range −1 < w < −1/3 depending on the position of the probe brane in the bulk. As the probe brane approaches the horizon of the background black hole, the inflation rate decreases and the value of w gets larger. At some critical distance away from the horizon, inflation ends. When the brane-universe reaches the horizon, the conformal invariance is restored, the background geometry becomes AdS 5 × S 5 , and the brane-universe feels the CFT thermal radiation and reheats.

Generating the curvature perturbation with instant preheating

“…Thus, our present model complements the original scenarios [11,13,14,22] to give the paradigm of generating the curvature perturbation at the end of inflation. 9 A conserved angular momentum may be significant in some other cases [37,38].…”

The cosmological slingshot scenario: a stringy early times universe

“…We will introduce our D3-brane universe in the background (1.4,1.5) (for type-0 backgrounds see [6]). In order to find analytical results, we will rely on the probebackground approximation, in which the backreaction of the probe brane onto the bulk fields is disregarded.…”

“…Under the above described assumptions, the brane action turns out to be 6) where the Lagrangian is given by…”

Cosmic acceleration driven by mirage inhomogeneities

“…The simplest case corresponds to a D3-brane moving in a static spherically symmetric gravitational background with a dilaton as well as a RR background C(r) = C 0...3 (r) with a self-dual tachyonic bulk field. In this case it is also possible to have a mechanism for the reheating of the Universe [4].…”