Related papers: The universal thermodynamic properties of Extremel…

We study the response of a static Unruh-DeWitt detector outside an exotic compact object (ECO) with a general reflective boundary condition in 3+1 dimensions. The horizonless ECO, whose boundary is extremely close to the would-be event…

Black holes are the fascinating objects in the universe. They represent extreme deformations in spacetime geometry. Here, we construct f(P) gravity and the first example of static-spherically symmetric black hole solution in f(P) gravity…

The frozen star is a recent proposal for a non-singular solution of Einstein's equations that describes an ultracompact object which closely resembles a black hole from an external perspective. The frozen star is also meant to be an…

The thermodynamical properties of dark energy are usually investigated with the equation of state $\omega =\omega_{0}+\omega_{1}z$. Recent observations show that our universe is accelerating, and the apparent horizon and the event horizon…

In this paper we find analytical expressions for thermodynamic quantities of scalar (tensor) and vector unparticle static black holes. We also find rotating solutions to these systems and analyse their thermodynamics. First we consider the…

The semiclassical approximation is studied on hypersurfaces approaching the union of future null infinity and the event horizon on a large class of four dimensional black hole backgrounds. Quantum fluctuations in the background geometry are…

The recent advancements in black hole imaging have opened a new era of probing horizon-scale physics with electromagnetic radiation. However, a feature of the observed images, a bright ring encircling a relatively dark region, has not…

We investigate the black holes properties with a very simple and semi-classical model of spacetime discretization. In this context, we apply the Heisenberg's uncertainty principle and the equipartition energy theorem to thereto, obtaining…

It is a common wisdom that properties of macroscopic bodies are well described by (semi)classical physics. As we have suggested this wisdom is not applicable to black holes. Despite being macroscopic, black holes are quantum objects. They…

We consider the energetics and thermodynamics of spacetimes with no horizons, but endowed with a preferred timelike junction surface. They could arise as a limiting case of the gravastar and other constructions regularizing the interior of…

The LIGO observation of gravitational waves from a binary black hole merger has begun a new era in fundamental physics. If new dark sector particles, be they bosons or fermions, can coalesce into exotic compact objects (ECOs) of…

We investigate thermodynamic equilibrium of a self-gravitating perfect fluid in a spherically symmetric system containing a black hole of mass M by means of the Tolman-Oppenheimer-Volkoff (TOV) equation. At r >> 2M its solutions describe a…

Deep conceptual problems associated with classical black holes can be addressed in string theory by the ``fuzzball'' paradigm, which provides a microscopic description of a black hole in terms of a thermodynamically large number of regular,…

The thermodynamics of black holes is shown to be directly induced by their near-horizon conformal invariance. This behavior is exhibited using a scalar field as a probe of the black hole gravitational background, for a general class of…

We study the physical properties of four-dimensional, string-theoretical, horizonless "fuzzball" geometries by imaging their shadows. Their microstructure traps light rays straying near the would-be horizon on long-lived, highly redshifted…

In this paper, we study the thermodynamical properties of the (2+1) dimensional black hole with a non-linear electrodynamics and with a negative cosmological constant, using the Generalized Uncertainty Principle (GUP). This approach shows…

String theory suggests that black hole microstates are quantum, horizon sized `fuzzballs', rather than smooth geometries with horizon. Radiation from fuzzballs can carry information and does not lead to information loss. But if we let a…

In the spherically symmetric case the Einstein field equations take on their simplest form for a matter-density rho = 1 / (8 pi r^2), from which a radial metric coefficient g_{rr} \propto r follows. The boundary of an object with such an…

It is argued that the qualitative features of black holes, regarded as quantum mechanical objects, depend both on the parameters of the hole and on the microscopic theory in which it is embedded. A thermal description is inadequate for…

In the presence of a minimal uncertainty in length, there exists a critical temperature above which the thermodynamics of a gas of radiation changes drastically. We find that the equilibrium temperature of a system composed of a…