Theory HEP Seminar

Wild and tame scalar-tensor black holes

Valerio Faraoni

Bishop's University

In scalar-tensor gravity (the prototype alternative to Einstein's theory hinted at by string theories and suggested as a possible explanation of the cosmic acceleration), black holes do not obey the Jebsen-Birkhoff theorem. Non-isolated black holes can be highly dynamical and the teleological concept of event horizon is replaced by the apparent or trapping horizon. Dynamical solutions describing inhomogeneities embedded in cosmological “backgrounds” and the phenomenology of their apparent horizons, which often appear/vanish in pairs, will be described. Isolated black holes, in contrast, are the same as in general relativity.