Related papers: Encoding beyond cosmological horizons in de Sitter…
Quantum gravity phenomenology suggests the interesting possibility that black holes are not eternal. Collapse could be halted by some unknown mechanism, or Hawking radiation might leave behind a regular spacetime. Here we investigate a…
We disclose the behaviour of quantum and classical correlations among all the different spatial-temporal regions of a space-time with an event horizon, comparing fermionic with bosonic fields. We show the emergence of conservation laws for…
Recently, new exploratory channels have opened up for the physics of highly compact objects, such as gravitational waves and black hole shadows. Moreover, more precise analysis and observations are now possible in the physics of accretion…
We argue that the entropy of a black hole is due to the entanglement of matter fields and gravitons across the horizon. While the entanglement entropy of the vacuum is divergent because of UV correlations, we show that low-energy…
This paper explores the enduring black hole information and firewall paradoxes, challenges that have prompted many proposals, conjectures, and theories. Noteworthy among these are the ER = EPR conjecture and AdS/CFT correspondence, which…
We argue that the complementarity picture, as interpreted as a reference frame change represented in quantum gravitational Hilbert space, does not suffer from the "firewall paradox" recently discussed by Almheiri, Marolf, Polchinski, and…
In this paper we will analyse the black hole information paradox in group field cosmology. We will first construct a group field cosmology with third quantized gauge symmetry. Then we will argue that that in this group field cosmology the…
The cosmological horizon has an associated entropy suggesting that it might encode a quantum mechanical system on its surface. This has motivated extending the principles of the anti-de Sitter (AdS) space/ conformal field theory (CFT)…
We study a gravity theory where a scalar field with potential, beyond its minimal coupling, is also coupled through a non-minimal derivative coupling with the torsion scalar which is the teleparallel equivalent of Einstein gravity. This…
Deviations from Hawking's thermal black hole spectrum, observable for macroscopic black holes, are derived from a model of a quantum horizon in loop quantum gravity. These arise from additional area eigenstates present in quantum surfaces…
Recent observations of the near-horizon regions of BHs, particularly the images captured by the Event Horizon Telescope (EHT) collaboration, have greatly advanced our understanding of gravity in extreme conditions. These images reveal a…
A new version of holographic principle for cosmology is proposed, which dictates that particle entropy within `cosmological apparent horizon' should not exceed gravitational entropy associated with the apparent horizon. It is shown that, in…
We describe some properties of the hyperbolically symmetric black hole (hereafter referred to as the $HSBH$) proposed a few years ago. We start by explaining the main motivation behind such an idea, and we determine the main differences…
It is well known that de Sitter(dS) black holes generally have a black hole horizon and a cosmological horizon, both of which have Hawking radiation. But the radiation temperature of the two horizons is generally different, so dS black…
We show that higher dimensional models (brane worlds) in which the scale of quantum gravity $M_*$ is much smaller than the apparent scale $M_P \sim 10^{19}$ GeV are in conflict with bounds arising from holography and black hole entropy. The…
A generalisation of the asymptotic wormhole boundary condition for the case of spacetimes with a cosmological horizon is proposed. In particular, we consider de Sitter spacetime with small cosmological constant. The wave functions selected…
Recent implications of results from quantum information theory applied to black holes has led to the confusing conclusions that requires either abandoning the equivalence principle (e.g. the firewall picture), or the no-hair theorem (e.g.…
How the supermassive black hole SgrA* in the Milky Way Center looks like for a distant observer? It depends on the black hole highlighting by the surrounding hot matter. The black hole shadow (the photon capture cross-section) would be…
Recently, several ways of obtaining observational proof of the existence of black-hole horizons have been proposed. We argue here that such proof is fundamentally impossible: observations can provide arguments, sometimes very strong ones,…
We argue that in the presence of instanton-like singularities, the existence of cosmological horizons can become frame-dependent, ie. a horizon which appears in Einstein frame may not appear in string frame. We speculate on the relation…