Thoughts on entropic gravity in the Parikh-Wilczek tunneling model of Hawking radiation

In this letter, we use the Parikh-Wilczek tunneling model of Hawking radiation to illustrate that a reformulation of Verlinde's entropic gravity is needed to derive the Newton's law for a temperature-varying screen, demanded by the conservation of energy. Furthermore, the entropy stored in the holographic screen is shown to be additive and its temperature dependence can be obtained.Comment: 5 pages, 1 figure, version submitted to EPJ

Nonthermal correction to black hole spectroscopy

Area spectrum of black holes have been obtained via various methods such as quasinormal modes, adiabatic invariance and angular momentum. Among those methods, calculations were done by assuming black holes in thermal equilibrium. Nevertheless, black holes in the asymptotically flat space usually have negative specific heat and therefore tend to stay away from thermal equilibrium. Even for those black holes with positive specific heat, temperature may still not be well defined in the process of radiation, due to the back reaction of decreasing mass. Respect to these facts, it is very likely that Hawking radiation is nonthermal and the area spectrum is no longer equidistant. In this note, we would like to illustrate how the area spectrum of black holes is corrected by this nonthermal effect.Comment: 12 pages, revtex

Finiteness of Entanglement Entropy in Quantum Black Hole

A logarithmic but divergent term usually appears in the computation of entanglement entropy circumferencing a black hole, while the leading quantum correction to the Bekenstein-Hawking entropy also takes the logarithmic form. A quench model of CFT within finite Euclidean time was proposed in the \cite{Kuwakino:2014nra} to regard this logarithmic term as entanglement between radiation and the black hole, and this proposal was justified by the alternative sign for $n$-partite quantum information. However, this preliminary form suffers from the notorious divergence at its low temperature limit. In this letter, we propose a modified form for black hole entanglement entropy such that the divergence sickness can be cured. We discuss the final stage of black hole due to this modification and its relation to R{\`e}nyi entropy, higher loop quantum correction and higher spin black holes.Comment: 8 pages, version submitted to EP

Quantum Order: a Quantum Entanglement of Many Particles

It is pointed out that quantum states, in general, contain a new kind of orders that cannot be characterized by symmetry. A concept of quantum order is introduced to describe such orders. As two concrete examples, we discussed quantum orders in free fermion systems and in 2D spin-1/2 systems. We generalize the Landau's theory for the classical orders and introduce projective symmetry group and Fermi surface topology to characterize different quantum orders.Comment: 4 pages, 1 figures, RevTeX4, homepage: http://dao.mit.edu/~we