Geon black holes and quantum field theory

Black hole spacetimes that are topological geons in the sense of Sorkin can be constructed by taking a quotient of a stationary black hole that has a bifurcate Killing horizon. We discuss the geometric properties of these geon black holes and the Hawking-Unruh effect on them. We in particular show how correlations in the Hawking-Unruh effect reveal to an exterior observer features of the geometry that are classically confined to the regions behind the horizons.Comment: 11 pages. Talk given at the First Mediterranean Conference on Classical and Quantum Gravity, Kolymbari (Crete, Greece), September 2009. Dedicated to Rafael Sorkin. v2: typesetting bug fixe