Time-dependent cosmologies and their duals

Abstract

We construct a family of solutions in IIB supergravity theory. These are time dependent or depend on a light-like coordinate and can be thought of as deformations of AdS 5 × S 5 . Several of the solutions have singularities. The light-like solutions preserve 8 supersymmetries. We argue that these solutions are dual to the N = 4 gauge theory in a 3 + 1 dimensional spacetime with a metric and a gauge coupling that is varying with time or the light-like direction respectively. This identification allows us to map the question of singularity resolution to the dual gauge theory.

Supersymmetric intersecting branes in time-dependent backgrounds

“…It is thus interesting to find if we can have such brane solutions in time-dependent backgrounds with time-dependent dilaton. In fact, D3-brane solutions have been found and discussed in [17,19] and other single brane solutions in [24,26]. A systematic derivation of the general brane solutions in the pp-wave backgrounds has been given in [32].…”

“…Note that u and v are null coordinates. The metric components Ξ, Z α , B and the dilaton Φ are assumed to be functions of u and r, whereas K depends on u, y α and r. Our ansatz includes more general solutions than those in [17,19], which consider only single D3-brane solutions with the metrics of product form of time-and space-dependent factors; ours allows intersecting branes as well as more general spacetime dependence.…”

Null deformed domain wall

“…As will be shown clearly below, the resulting configuration can be seen as the generalization of the light-like deformation of AdS 5 × S 5 studied in [1,2,3], from an effective five dimensional point of view. 9 For convenience, we name it as "Null-deformed domain wall", or shortly NDDW, while we will refer to the non deformed flat domain wall simply as DW.…”

“…14 In that follows, we will focus over the cases: a)(n V , n H ) = (0, 2); b) (n V , n H ) = (2, 0). In particular we consider the group manifolds Sp(2,1) Sp(1,1)×Sp (1) and SO (2,1) SO (2) . The solutions we obtain are peculiar because the warp-factor β turns out to be a function of r only, remaining untouched by the deformation.…”

“…In doing so, we are in part inspired by [1,2,3], 1 where a null deformation of AdS 5 × S 5 is considered. The authors propose an extension of the AdS/CFT correspondence to such background, that is the near horizon limit of a null deformed stack of D3-branes (the null deformation of intersecting brane configurations has been recently considered in [5]).…”