Analogue Gravity

Abstract

Analogue models of (and for) gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing) and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity).

Emergent perspective of gravity and dark energy

“…(For a review, see [1] and [2]; for a small sample of work in the same spirit, see [3][4][5][6][7][8].) Given the intimate connection between gravity and cosmology, such a change in perspective has important implications for cosmology.…”

Hawking-Like Radiation Does Not Require a Trapped Region

“…It is sufficient to set up a dynamically changing flow asymptotically approaching a sonic regime with sufficient rapidity in laboratory time. Introduction: It is by now well established that the physics associated with classical and quantum fields in curved spacetimes can be reproduced, within certain approximations, in a variety of different physical systems by constructing so-called "analogue spacetimes" [1,2]. Among such systems the simplest example is provided by a barotropic, irrotational and viscosity-free fluid.…”

Astrophysical implications of the Asymptotic Safety Scenario in Quantum Gravity

“…The limitation of this approach lies in the fact that in general the improved metric may not be a solution of Einstein equation, but one can imagine that this is a sort of "Thomas-Fermi" approximation where only the leading quantum corrections are taken into account [30,31]. The improved g µν (k) metric represents then a sort of "emergent" spacetime description of the effective geometry [32][33][34] according to the scale dependence of the Newton constant.…”