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Toroidal horizons in binary black hole inspirals

Cohen, Michael I. and Kaplan, Jeffrey D. and Scheel, Mark A. (2012) Toroidal horizons in binary black hole inspirals. Physical Review D, 85 (2). Art. No. 024031. ISSN 0556-2821.

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We examine the structure of the event horizon for numerical simulations of two black holes that begin in a quasicircular orbit, inspiral, and finally merge. We find that the spatial cross section of the merged event horizon has spherical topology (to the limit of our resolution), despite the expectation that generic binary black hole mergers in the absence of symmetries should result in an event horizon that briefly has a toroidal cross section. Using insight gained from our numerical simulations, we investigate how the choice of time slicing affects both the spatial cross section of the event horizon and the locus of points at which generators of the event horizon cross. To ensure the robustness of our conclusions, our results are checked at multiple numerical resolutions. Three-dimensional visualization data for these resolutions are available for public access online. We find that the structure of the horizon generators in our simulations is consistent with expectations, and the lack of toroidal horizons in our simulations is due to our choice of time slicing.

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Additional Information:© 2012 American Physical Society. Received 7 October 2011; published 18 January 2012. We would like to thank Saul Teukolsky, Jeff Winicour, and Aaron Zimmerman for useful discussions on toroidal horizons. We would especially like to thank Jeandrew Brink for a careful reading of a draft of this manuscript and many useful suggestions for improvement. Thanks to Nick Taylor for experimenting with modified gauge conditions designed to retard the lapse function.We would also like to acknowledge Fan Zhang and Béla Szilágyi for interesting thoughts on why our numerical slicings have not resulted in toroidal event horizons. J. K. would like to thank David Nichols for a useful discussion on the numerical resolution of a toroidal horizon. M. C. would like to thank Matt Robbins and Joerg Wachner for designing Figs. 3–6. This work was supported in part by grants from the Sherman Fairchild Foundation and from the Brinson Foundation, by NSF Grants No. PHY-1068881 and No. PHY-1005655, by NASA Grant No. NNX09AF97G, and by NASA APT Grant No. NNX11AC37G.
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Sherman Fairchild FoundationUNSPECIFIED
Brinson FoundationUNSPECIFIED
Classification Code:PACS: 04.25.D-, 04.20.-q, 04.20.Gz, 04.25.dg
Record Number:CaltechAUTHORS:20120302-140710339
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Official Citation:Toroidal horizons in binary black hole inspirals Michael I. Cohen, Jeffrey D. Kaplan, and Mark A. Scheel Published 18 January 2012 (13 pages) 024031
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29572
Deposited By: Ruth Sustaita
Deposited On:02 Mar 2012 22:25
Last Modified:26 Dec 2012 14:54

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