Superrotation charge and supertranslation hair on black holes
It is shown that black hole spacetimes in classical Einstein gravity are characterized by, in addition to their ADM mass M, momentum $$\vec{P}$$, angular momentum $$\vec{J}$$ and boost charge $$\vec{/k}$$ , an infinite head of supertranslation hair. Furthermore, the distinct black holes are distinguished by classical superrotation charges measured at infinity. Solutions with supertranslation hair are diffeomorphic to the Schwarzschild spacetime, but the diffeomorphisms are part of the BMS subgroup and act nontrivially on the physical phase space. It is shown that a black hole can be supertranslated by throwing in an asymmetric shock wave. We derive a leadingorder Bondigauge expression for the linearized horizon supertranslation charge and shown to generate, via the Dirac bracket, supertranslations on the linearized phase space of gravitational excitations of the horizon. The considerations of this paper are largely classical augmented by comments on their implications for the quantum theory.
 Authors:

^{[1]};
^{[1]};
^{[2]}
 Univ. of Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics (DAMTP)
 Harvard Univ., Cambridge, MA (United States). Center for the Fundamental Laws of Nature
 Publication Date:
 Grant/Contract Number:
 FG0291ER40654
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of High Energy Physics (Online)
 Additional Journal Information:
 Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2017; Journal Issue: 5; Journal ID: ISSN 10298479
 Publisher:
 Springer Berlin
 Research Org:
 Harvard Univ., Cambridge, MA (United States)
 Sponsoring Org:
 USDOE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Black Holes; Gauge Symmetry; Nonperturbative Effects
 OSTI Identifier:
 1374982
Hawking, Stephen W., Perry, Malcolm J., and Strominger, Andrew. Superrotation charge and supertranslation hair on black holes. United States: N. p.,
Web. doi:10.1007/JHEP05(2017)161.
Hawking, Stephen W., Perry, Malcolm J., & Strominger, Andrew. Superrotation charge and supertranslation hair on black holes. United States. doi:10.1007/JHEP05(2017)161.
Hawking, Stephen W., Perry, Malcolm J., and Strominger, Andrew. 2017.
"Superrotation charge and supertranslation hair on black holes". United States.
doi:10.1007/JHEP05(2017)161. https://www.osti.gov/servlets/purl/1374982.
@article{osti_1374982,
title = {Superrotation charge and supertranslation hair on black holes},
author = {Hawking, Stephen W. and Perry, Malcolm J. and Strominger, Andrew},
abstractNote = {It is shown that black hole spacetimes in classical Einstein gravity are characterized by, in addition to their ADM mass M, momentum $\vec{P}$, angular momentum $\vec{J}$ and boost charge $\vec{/k}$ , an infinite head of supertranslation hair. Furthermore, the distinct black holes are distinguished by classical superrotation charges measured at infinity. Solutions with supertranslation hair are diffeomorphic to the Schwarzschild spacetime, but the diffeomorphisms are part of the BMS subgroup and act nontrivially on the physical phase space. It is shown that a black hole can be supertranslated by throwing in an asymmetric shock wave. We derive a leadingorder Bondigauge expression for the linearized horizon supertranslation charge and shown to generate, via the Dirac bracket, supertranslations on the linearized phase space of gravitational excitations of the horizon. The considerations of this paper are largely classical augmented by comments on their implications for the quantum theory.},
doi = {10.1007/JHEP05(2017)161},
journal = {Journal of High Energy Physics (Online)},
number = 5,
volume = 2017,
place = {United States},
year = {2017},
month = {5}
}