Related papers: Energy of 4-Dimensional Black Hole, etc
The energy associated with a static and spherically symmetric charged dilaton black hole is obtained for arbitrary value of the coupling parameter (which regulates the strength of the coupling of the dilaton to the Maxwell field) $\beta$.…
Quintessential dark energy with pressure $p$ and density $\rho$ is related by equation of state $p=\omega\rho$ with the state parameter $-1<\omega<-1/3$. The cosmological dark energy influence on black hole spacetime are interesting and…
In this paper we study the accretion of dark energy onto a black hole in the cases that dark energy is equipped with a positive cosmological constant and when the space-time is described by a Schwarzschild-de Sitter metric. It is shown…
In this thesis, we explore the possibility to define black hole mass in terms of the Weyl tensor for the entire family of Lovelock-AdS gravity theories. The level of degeneracy $k$ of the corresponding vacuum fixes the number of curvatures…
We discuss masses of stellar black holes found in binary systems and errors in their determination. The observed mass distribution has a broad shape within the range $4-16 M_\odot$ without visible concentration to some preferred value. On…
In the Letter [1] (also [2]) there is a claim that the generalised second law of thermodynamics (entropy increase) for black holes provides some limits on the rate of variation of the fundamental constants of nature (electric charge e,…
Our goal in this paper is to explain the internal properties of the black hole by considering its density as a function of the reciprocal of its radius and the temperature as a function of the reciprocal of the density. We then set the…
Calculations of the inner mass function of the Hayward regular black hole with fluxes are reviewed and rederived. We present detailed calculations of the inner mass function in two forms of the Ori approach (the ingoing flux is continuous,…
We revisit here a recent work on regular rotating black holes. We introduce a new mass function generalizing the commonly used Bardeen and Hayward mass functions and extend the recently proposed solutions in order to accommodate a…
Finite-time thermodynamics provides the means to revisit ideal thermodynamic equilibrium processes in the light of reality and investigate the energetic "price of haste", i.e. the consequences of carrying out a process in finite time, when…
We discuss and compare different definitions of the entropy of a black hole. In particular we show that the thermodynamical entropy defined by the response of the free energy of a black hole to the change of temperature does not coincide…
In this work we derive novel analytical expressions for the mass and distance of a Schwarzschild black hole (BH), as well as for the orbital radius of test particles orbiting it, it terms of astrophysical observables measured throughout the…
The black hole mass measurement in active galaxies is a challenge, particularly in sources where the reverberation method cannot be applied. We aim to determine the black hole mass in a very special object, RE J1034+396, one of the two AGN…
We propose a logarithmic parametrization form of energy density for the scalar field dark energy in the framework of the standard theory of gravity, which supports the necessary transition from the decelerated to the accelerated behavior of…
Trying to interpret recent matrix model results (hep-th/0101011) we discuss computation of classical free energy of exact dilatonic 2-d black hole from the effective action of string theory. The euclidean space-time action evaluated on the…
We explain in detail how to calculate the gravitational mass and angular momentum multipoles of the most general non-extremal four-dimensional black hole with four magnetic and four electric charges. We also calculate these multipoles for…
It was recently suggested (arxiv:2410.06604) that the small value of the dark energy of the universe could be explained in terms of the scale of neutrino masses through a simple quantum field theoretic mechanism. I clarify that the quantity…
The dark energy issue is focusing the attention of an incresing number of physicists all over the world. Among the possible alternatives in order to explain what as been named the "Mystery of the Millennium" are the so-called Modified…
In gr-qc/9908036 [Phys. Lett. A 265 (2000) 1] a new method was given which naturally led to a quantum of mass equal to twice the Planck mass. In the present note which, for convenience, we write formally as a continuation of that paper, we…
We develop a simple physical model to describe the dynamics of a massive point-like object, such as a black hole, near the center of a dense stellar system. It is shown that the total force on this body can be separated into two independent…