2008/10/15 by Henriette Elvang, Pau Figueras, Elvang, Henriette +7 · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Relativity and Gravitational Theory #gr-qc #hep-th
paper · pdf · doi:10.48550/arxiv.0810.2778
35 pages, 4 appendices, 18 figures
arxiv created 2008/10/15 · openalex publication_date 2008/10/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We study mergers of ergoregions in d+1-dimensional vacuum gravity. At the merger point, where the ergosurfaces bounding each ergoregion just touch, solutions exhibit universal behavior when there is rotation only in one plane: the angle between the merging ergosurfaces depends only on the symmetries of the solution, not on any other details of the configuration. We show that universality follows from the fact that the relevant component of Einstein's equation reduces to Laplace equation at the point of merger. Thus ergoregion mergers mimic mergers of Newtonian equipotentials and have similar universal behavior. For solutions with rotation in more than one plane, universality is lost. We demonstrate universality and non-universality in several explicit examples.