Strong cosmic censorship for a black hole in loop quantum gravity

A fine gravitational theory is essentially expected to deal with the problem of spacetime singularities. Loop quantum gravity as one branch of quantum gravity is potential to explore the nature of black holes. Recently, according to the quantum Oppenheimer-Snyder model in loop quantum cosmology, a novel loop quantum corrected black hole in de Sitter spacetime has been discovered. Here, we focus on examining the strong cosmic censorship(SCC) based on such a quantum modified black hole by considering a massless neutral scalar field perturbation. As a result, we find that the SCC is destroyed as the black hole approaches to the near-extremal limit. Notably, the critical value of the black hole mass ratio for such a violation increases with the increase of the cosmological constant. It was implied the cosmological constant plays an important role in moderating the violation of the SCC

Effect of Earth's rotation on the trajectories of free-fall bodies in Equivalence Principle Experiment

Owing to Earth's rotation a free-fall body would move in an elliptical orbit rather than along a straight line forward to the center of the Earth. In this paper on the basis of the theory for spin-spin coupling between macroscopic rotating bodies we study violation of the equivalence principle from long-distance free-fall experiments by means of a rotating ball and a non-rotating sell. For the free-fall time of 40 seconds, the difference between the orbits of the two free-fall bodies is of the order of 10^{-9}cm which could be detected by a SQUID magnetometer owing to such a magnetometer can be used to measure displacements as small as 10^{-13} centimeters.Comment: 6 pages, 4 figure