Black Hole Entropy from Soft Hair


Perry, M. (2019). Black Hole Entropy from Soft Hair. Perimeter Institute. https://pirsa.org/19100078


Perry, Malcolm. Black Hole Entropy from Soft Hair. Perimeter Institute, Oct. 17, 2019, https://pirsa.org/19100078


          @misc{ pirsa_19100078,
            doi = {10.48660/19100078},
            url = {https://pirsa.org/19100078},
            author = {Perry, Malcolm},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {Black Hole Entropy from Soft Hair},
            publisher = {Perimeter Institute},
            year = {2019},
            month = {oct},
            note = {PIRSA:19100078 see, \url{https://pirsa.org}}

Malcolm Perry University of Cambridge


Black Hole Entropy is a well established concept and arises naturally once one realises that black holes are characterised by a temperature. Boltzmann established that entropy can be regarded as the logarithm of the density of states function. However, black hole uniqueness theorems appeared to indicate that black holes have no hair. I will describe a loophole in the no-hair theorems and how black holes can have an infinite set of charges related to "large" gauge transformations. I will then use these ideas to show that on sections of the horizon there is a holographic conformal field theory. The temperature of this conformal theory means that it has a statistical entropy that reproduces the Hawking formula. The implications of this for the black hole information paradox will be briefly described.