Lovelock theories, holography and the fate of the viscosity bound release_u7sgicorj5dm3pubelvlczwxw4

by Xian O. Camanho, Jose D. Edelstein, Miguel F. Paulos

Released as a article .

2010  

Abstract

We consider Lovelock theories of gravity in the context of AdS/CFT. We show that, for these theories, causality violation on a black hole background can occur well in the interior of the geometry, thus posing more stringent constraints than were previously found in the literature. Also, we find that instabilities of the geometry can appear for certain parameter values at any point in the geometry, as well in the bulk as close to the horizon. These new sources of causality violation and instability should be related to CFT features that do not depend on the UV behavior. They solve a puzzle found previously concerning unphysical negative values for the shear viscosity that are not ruled out solely by causality restrictions. We find that, contrary to previous expectations, causality violation is not always related to positivity of energy. Furthermore, we compute the bound for the shear viscosity to entropy density ratio of supersymmetric conformal field theories from d=4 till d=10 - i.e., up to quartic Lovelock theory -, and find that it behaves smoothly as a function of d. We propose an approximate formula that nicely fits these values and has a nice asymptotic behavior when d goes to infinity for any Lovelock gravity. We discuss in some detail the latter limit. We finally argue that it is possible to obtain increasingly lower values for the shear viscosity to entropy density ratio by the inclusion of more Lovelock terms.
In text/plain format

Archived Files and Locations

application/pdf  2.7 MB
file_fyfcbm2xgneu7bmywtatnflgye
arxiv.org (repository)
web.archive.org (webarchive)
application/pdf  2.7 MB
file_2ku6jxevojh2pdms6nx6bjvsym
archive.org (archive)
web.archive.org (webarchive)
arxiv.org (repository)
core.ac.uk (web)
Read Archived PDF
Preserved and Accessible
Type  article
Stage   accepted
Date   2010-12-21
Version   v2
Language   en ?
arXiv  1010.1682v2
Work Entity
access all versions, variants, and formats of this works (eg, pre-prints)
Catalog Record
Revision: d043d72a-7e0c-4638-bafc-60f133b3c7b3
API URL: JSON