# GMR

## Seminar

### Self-similar gravitational collapse and gravitational instantons

Seminar Room 1, Newton Institute

#### Abstract

I will first describe some of my work with Hartnoll and Pope(hep-th/0208031) on the {\sl linear} (instability) of higher dimensional black holes, particularly those constructed from B\"ohm metrics on $S^5$. I shall then go on to relate this to the the fully {\ls non-linear} numerical studies of Bizon, Chmaj and Schmidt (gr-qc/0506074) on Bianchi IX Black holes in five spacetime dimensions. Certain gravitational instanstons, whose linear stability properties are known, figure as ultra-static solutions. I will present an exact time dependent solution found in (hep-th/0501117). Using Kaluza-Klein theory, I will make connections with spherically symmetric collapse of magnetically, and by electric-magnetic-magnetic duality, electrically charged black holes in four spacetime dimensions.