title: Initial data for black holes and black strings in 5D.
abstract: We explore time-symmetric hypersurfaces containing apparent horizons of black objects in a 5D spacetime with one coordinate compactified on a circle. We find a phase transition within the family of such hypersurfaces: the horizon has different topology for different parameters. The topology varies from S3 to S2 x S1. This phase transition is discontinuous--the topology of the horizon changes abruptly. We explore the behavior around the critical point and present a possible phase diagram.
authors.affiliation: Racah Institute of Physics, The Hebrew University, Jerusalem, 91904, Israel.
authors.forename: Evgeny
authors.initials: E
authors.lastname: Sorkin
authors.forename: Tsvi
authors.initials: T
authors.lastname: Piran