Spradlin, MarcusStrominger, Andrew2019-09-271999Spradlin, Marcus, and Andrew Strominger. 1999. “Vacuum States for AdS2 Black Holes.” Journal of High Energy Physics 1999 (11): 021–021. https://doi.org/10.1088/1126-6708/1999/11/021.1029-84791126-6708http://nrs.harvard.edu/urn-3:HUL.InstRepos:41417227An AdS(2) black hole spacetime is an AdS(2) spacetime together with a preferred choice of time. The Boulware, Hartle-Hawking and SL(2; R) invariant vacua are constructed, together with their Green functions and stress tensors, for both massive and massless scalars in an AdS(2) black hole. The classical Bekenstein-Hawking entropy is found to be independent of the temperature, but at one loop a non-zero entanglement entropy arises. This represents a logarithmic violation of finite-temperature decoupling for AdS(2) black holes which arise in the near-horizon limit of an asymptotically at black hole. Correlation functions of the SL(2; R) invariant boundary quantum mechanics are computed as functions of the choice of AdS(2) vacuum.en-USJournal Article2019-09-2710.1088/1126-6708/1999/11/021