Impossibility of superluminal travel in Lorentz violating theories
Authors: Coutant A., Finazzi S., Liberati S., Parentani R.
Autors Affiliation: Laboratoire de Physique Théorique, CNRS UMR 8627, Bât. 210, Université Paris-Sud 11, 91405 Orsay Cedex, France; INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, via Sommarive 14, 38123 Povo-Trento, Italy; SISSA, Via Bonomea 265, 34136, Trieste, Italy and INFN, Sezione di Trieste
Abstract: Warp drives are space-times allowing for superluminal travel. However, they are quantum mechanically unstable because they produce a Hawking-like radiation which is blue shifted at their front wall without any bound. We reexamine this instability when local Lorentz invariance is violated at ultrahigh energy by dispersion, as in some theories of quantum gravity. Interestingly, even though the ultraviolet divergence is now regulated, warp drives are still unstable. Moreover the type of instability is different whether one uses a subluminal or a superluminal dispersion relation. In the first case, a black-hole laser yields an exponential amplification of the emitted flux whereas, in the second, infrared effects produce a linear growth of that flux. These results suggest that chronology could still be protected when violating Lorentz invariance.
Journal/Review: PHYSICAL REVIEW D
Volume: 85 (6) Pages from: 064020 to: 064020
More Information: S. F. has been supported by the Foundational Questions Institute (FQXi) Grant No. FQXi-MGA-1002.DOI: 10.1103/PhysRevD.85.064020Citations: 5data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-02-23References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here