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SUMMARY:Soft Hair on Black Holes II - Malcolm Perry (DAMTP)
DTSTART:20160219T130000Z
DTEND:20160219T140000Z
UID:TALK63409@talks.cam.ac.uk
CONTACT:43345
DESCRIPTION:It has recently been shown that BMS supertranslation symmetrie
 s imply an infinite number of conservation laws for all gravitational theo
 ries in asymptotically Minkowskian spacetimes. These laws require black ho
 les to carry a large amount of soft (i.e. zero-energy) supertranslation ha
 ir. The presence of a Maxwell field similarly implies soft electric hair. 
 This paper gives an explicit description of soft hair in terms of soft gra
 vitons or photons on the black hole horizon\, and shows that complete info
 rmation about their quantum state is stored on a holographic plate at the 
 future boundary of the horizon. Charge conservation is used to give an inf
 inite number of exact relations between the evaporation products of black 
 holes which have different soft hair but are otherwise identical. It is fu
 rther argued that soft hair which is spatially localized to much less than
  a Planck length cannot be excited in a physically realizable process\, gi
 ving an effective number of soft degrees of freedom proportional to the ho
 rizon area in Planck units. 
LOCATION:Pavilion B Potter Room (B1.19)
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