End Point of the Ultraspinning Instability and Violation of Cosmic Censorship

We thank Roberto Emparan for discussions and Juha Jaykka and Kacper Kornet for their technical support. We thank the grchombo team for the great collaboration. Part of the computations for this Letter were undertaken on the COSMOS Shared Memory system at DAMTP (University of Cambridge). COSMOS is operated on behalf of the STFC DiRAC HPC Facility and is funded by BIS National E-infrastructure capital Grant No. ST/ J005673/1 and STFC Grants No. ST/H008586/1, No. ST/ K00333X/1. We thankfully acknowledge the computer resources at MareNostrum and the technical support provided by Barcelona Supercomputing Center (FI-2016-3-0006 “New frontiers in numerical general relativity”). P. F. and S. T. are supported by the European Research Council Grant No. ERC-2014-StG 639022-NewNGR. P. F. is also supported by a Royal Society University Research Fellowship (Grant No. UF140319). M. K. is supported by an STFC studentship. L. L. is supported by NSERC, CIFAR and Perimeter Institute. This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant agreement No. 690904. P. F. and M. K. would like to thank Perimeter Institute for their hospitality during the final stages of this work. Research at Perimeter Institute is supported by the Government of Canada through the Department of Innovation, Science and Economic Development Canada, and by the Province of Ontario through the Ministry of Research and Innovation.