A Caltech Library Service

Revisiting event horizon finders

Cohen, Michael I. and Pfeiffer, Harald P. and Scheel, Mark A. (2009) Revisiting event horizon finders. Classical and Quantum Gravity, 26 (3). 035005. ISSN 0264-9381.

[img] PDF - Published Version
Restricted to Repository administrators only
See Usage Policy.


Use this Persistent URL to link to this item:


Event horizons are the defining physical features of black hole spacetimes, and are of considerable interest in studying black hole dynamics. Here, we reconsider three techniques to find event horizons in numerical spacetimes: integrating geodesics, integrating a surface, and integrating a level-set of surfaces over a volume. We implement the first two techniques and find that straightforward integration of geodesics backward in time is most robust. We find that the exponential rate of approach of a null surface towards the event horizon of a spinning black hole equals the surface gravity of the black hole. In head-on mergers we are able to track quasi-normal ringing of the merged black hole through seven oscillations, covering a dynamic range of about 10^5. Both at late times (when the final black hole has settled down) and at early times (before the merger), the apparent horizon is found to be an excellent approximation of the event horizon. In the head-on binary black hole merger, only some of the future null generators of the horizon are found to start from past null infinity; the others approach the event horizons of the individual black holes at times far before merger.

Item Type:Article
Related URLs:
URLURL TypeDescription
Pfeiffer, Harald P.0000-0001-9288-519X
Additional Information:© 2009 IOP Publishing Limited 2009. Print publication: Issue 3 (7 February 2009); received 16 September 2008, in final form 10 November 2008; published 13 January 2009. We gratefully acknowledge useful discussions with Lee Lindblom, Peter Diener, Saul Teukolsky and Kip Thorne. We particularly thank Kip Thorne for pointing out the relationship between the surface gravity and the rate of divergence of geodesics from the EH. This work was supported by grants from the Sherman Fairchild Foundation and the Brinson Foundation, and by NSF grants PHY-0601459, PHY-0652995, DMS-0553302 and NASA grant NNG05GG52G.
Funding AgencyGrant Number
Sherman Fairchild FoundationUNSPECIFIED
Brinson FoundationUNSPECIFIED
Issue or Number:3
Record Number:CaltechAUTHORS:20090722-142406238
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14639
Deposited By: Jason Perez
Deposited On:08 Aug 2009 19:59
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page