Matt Visser

TL;DR: In this paper, the authors consider the black-bounce-Reissner-Nordstrøm and black-Bounce-Kerr-Newman spacetimes as simple and clean everywhere-regular black hole "mimickers" that deviate from the Kerr-newman family in a precisely controlled and minimal manner and smoothly interpolate between regular black holes and traversable wormholes.

TL;DR: In this article, the authors show that in zero-viscosity, stationary fluid flow with generic boundary conditions, the creation of an acoustic horizon is accompanied by a formally infinite ''surface gravity'' and formally infinite "Hawking flux", and that these quantities can be kept finite only by applying a suitable nonconstant external body force, and for very specific boundary conditions on the flow.

TL;DR: In this article, a geometric classification of all spherically symmetric spacetimes that could result from singularity regularization is presented, using a kinematic construction that is both exhaustive and oblivious to the dynamics of the fields involved.

TL;DR: The authors provided an elementary introduction to the qualitative and quantitative results of velocity combination in special relativity, including the Wigner rotation and Thomas precession, in arguments presented at three differing levels: (1) utterly elementary, which will suit a first course in relativity; (2) intermediate, to suit a second course; and (3) advanced, to fit higher level students.

TL;DR: In this paper, the power-counting renormalizability of a z>=d variant of Horava gravity in (d+1) dimensions has been discussed and the implications for Horava's model of quantum gravity.