FRW solutions and holography from uplifted AdS/CFT

TL;DR

This paper constructs cosmological solutions from AdS/CFT dual pairs, analyzes their holographic properties, and explores the evolution of degrees of freedom and entropy in a time-dependent setting, linking higher-dimensional gravity to lower-dimensional effective theories.

Contribution

It introduces simple FRW solutions sourced by magnetic flavor branes and develops a holographic framework with a time-dependent warped metric to study cosmological evolution.

Findings

Finite cutoff and propagating graviton at finite times

Late-time divergence of Planck mass and entropy

Growth of degrees of freedom matches microscopic state count

Abstract

Starting from concrete AdS/CFT dual pairs, one can introduce ingredients which produce cosmological solutions, including metastable de Sitter and its decay to non-accelerating FRW. We present simple FRW solutions sourced by magnetic flavor branes and analyze correlation functions and particle and brane dynamics. To obtain a holographic description, we exhibit a time-dependent warped metric on the solution and interpret the resulting redshifted region as a Lorentzian low energy effective field theory in one fewer dimension. At finite times, this theory has a finite cutoff, a propagating lower dimensional graviton and a finite covariant entropy bound, but at late times the lower dimensional Planck mass and entropy go off to infinity in a way that is dominated by contributions from the low energy effective theory. This opens up the possibility of a precise dual at late times. We reproduce the time-dependent growth of the number of degrees of freedom in the system via a count of available microscopic states in the corresponding magnetic brane construction.