Long-Range Quantum Gravity

Abstract

It is a tantalising possibility that quantum gravity (QG) states remaining coherent at astrophysical, galactic and cosmological scales could exist and that they could play a crucial role in understanding macroscopic gravitational effects. We explore, using only general principles of General Relativity, quantum and statistical mechanics, the possibility of using long-range QG states to describe black holes. In particular, we discuss in a critical way the interplay between various aspects of long-range quantum gravity, such as the holographic bound, classical and quantum criticality and the recently proposed quantum thermal generalisation of Einstein’s equivalence principle. We also show how black hole thermodynamics can be easily explained in this framework.

Unitarity and Page Curve for Evaporation of 2D AdS Black Holes

“…The interpretation of the black hole entropy as the semiclassical limit of the EE of some microscopic quantum gravity (QG) DOF localized in the black hole interior is also consistent with the proposal of [ 78 ], which sees black hole thermodynamics as a manifestation of long-range quantum gravity effects. In particular, the (generalized) thermal equivalence principle (GTEP) [ 79 ], which is used to explain the Hawking temperature, should be seen as a universal property of semiclassical horizons in the sense explained above.…”

“…It is also interesting to notice that the derivation above is fully consistent with a corpuscular description of the black hole [ 78 ], i.e., its description in terms of a bound state of n quanta of number of species, with energy of the order of the temperature of the black hole, i.e., . The corresponding infinitesimal change of the black hole mass when n quanta are emitted is therefore .…”

Quasi-normal modes and Microscopic Structure of the Schwarzschild Black Hole

“…Similarly to what happens for the surface gravity of a black hole (see Ref. [15]), the quantum nature of Eq. ( 1) is obscured (the Planck constant does not appear) by expressing ω n in terms of the black-hole mass M , but becomes fully evident when we express it in terms of the black hole temperature T H .…”

“…In fact, in the case of AdS black holes, the damping of QNMs can be mapped into the thermalization of the conformal field theory on the boundary [10]. On the other hand, the emergent and corpuscular gravity scenarios suggest that black holes could be characterized by long-range quantum gravity effects of N quanta building the black hole [11][12][13][14][15][16]. Similarly to what happens for the surface gravity of a black hole (see Ref.…”

“…For a black hole, on the other hand, the mass M and the entropy S are fixed by the temperature or, equivalently, by the horizon radius r h . From a corpuscular gravity point of view, moreover, we can consider the black hole as a macroscopic quantum state that saturates a maximally packaging condition [16,[19][20][21], which has been shown to be equivalent to the holographic scaling of N [15]. Essentially, in a black hole of a given mass, we can "pack" a maximum amount of degrees of freedom, which is constrained by the size of the system.…”