Timescale for trans-Planckian collisions in Kerr spacetimeMandar Patil, Pankaj S. Joshi, Ken-ichi Nakao, Masashi Kimura and Tomohiro HaradaEPL, 110 3 (2015) 30004DOI: https://doi.org/10.1209/0295-5075/110/30004