Conformal invariance of black hole temperature

T Jacobson, G Kang
1993 Classical and quantum gravity  
It is shown that the surface gravity and temperature of a stationary black hole are invariant under conformal transformations of the metric that are the identity at infinity. More precisely, we find a conformal invariant definition of the surface gravity of a conformal Killing horizon that agrees with the usual definition(s) for a true Killing horizon and is proportional to the temperature as defined by Hawking radiation. This result is reconciled with the intimate relation between the trace
more » ... maly and the Hawking effect, despite the noninvariance of the trace anomaly under conformal transformations.
doi:10.1088/0264-9381/10/11/002 fatcat:fxqotwbvf5ed3ltvicgofiizjm