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SUMMARY:Black hole instabilities and local Penrose inequalities - Keiju Mu
 rata (DAMTP)
DTSTART:20111021T120000Z
DTEND:20111021T130000Z
UID:TALK34103@talks.cam.ac.uk
CONTACT:Ian A. Morrison
DESCRIPTION:Various higher-dimensional black holes have been shown to be u
 nstable by studying linearized gravitational perturbations. A simpler meth
 od for demonstrating instability is to find initial data that describes a 
 small perturbation of the black hole and violates a Penrose inequality. An
  easy way to construct initial data is by conformal rescaling of the unper
 turbed black hole initial data. For a compactified black string\, we const
 ruct initial data which violates the inequality almost exactly where the G
 regory-Laflamme instability appears. We then use the method to confirm the
  existence of the "ultraspinning" instability of Myers-Perry black holes. 
 Finally we study black rings. We show that "fat" black rings are unstable.
  We find no evidence of any rotationally symmetric instability of "thin" b
 lack rings.
LOCATION:Pavilion B Potter Room (B1.19)
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