arXiv subjects

I. Radinschi

Publications and source records attributed to I. Radinschi.

At least 19 recordsLinked to original sources

arXiv2020

Localization of Energy and Momentum in an Asymptotically Reissner-Nordström Non-singular Black Hole Space-time Geometry

The space-time geometry exterior to a new four-dimensional, spherically symmetric and charged black hole solution that, through a coupling of general relativity with a non-linear electrodynamics, is everywhere non-singular, for small $r$ it behaves as a de Sitter metric, and asymptotically it behaves as the Reissner-Nordström metric, is considered in order to study the energy-momentum localization. For the calculation of the energy and momentum distributions, the Einstein, Landau-Lifshitz, Weinberg and Møller energy-momentum complexes have been applied. The results obtained show that in all prescriptions the energy depends on the mass $M$ of the black hole, the charge $q$, two parameters $% a\in \mathbb{Z}^+$ and $γ\in \mathbb{R}^+$, and on the radial coordinate $r$. The calculations performed in each prescription show that all the momenta vanish. Additionally, some limiting and particular cases for $r$ and $q$ are studied, and a possible connection with strong gravitational lensing and micro lensing is attempted.

gr-qc↗

arXiv2019

Energy-Momentum Distribution in General Relativity for a Phantom Black Hole Metric

We use the Møller and Landau-Lifshitz energy-momentum definitions in General Relativity (GR) to evaluate the energy-momentum distribution of the phantom black hole space-time. The phantom black hole model was applied to the supermassive black hole at the Galactic Centre. We obtain that in both pseudotensorial prescriptions the energy distribution depends on the mass $M$ of the black hole, the phantom constant $p$ and the radial coordinate $r$. Further, all the calculated momenta are found to be zero. The limiting cases $r\rightarrow 0$, $r\rightarrow \infty $ and $r\rightarrow -\infty $ have also been the subject of the study.

gr-qc↗

arXiv2019

On the energy of a non-singular black hole solution satisfying the weak energy condition

The energy-momentum localization for a new four-dimensional and spherically symmetric, charged black hole solution that through a coupling of general relativity with non-linear electrodynamics is everywhere non-singular while it satisfies the weak energy condition is investigated. The Einstein and M\{o} ller energy-momentum complexes have been employed in order to calculate the energy distribution and the momenta for the aforesaid solution. It is found that the energy distribution depends explicitly on the mass and the charge of the black hole, on two parameters arising from the space-time geometry considered, and on the radial coordinate. Further, in both prescriptions all the momenta vanish.In addition, a comparison of the results obtained by the two energy-momentum complexes is made, whereby some limiting and particular cases are pointed out.

gr-qc↗

arXiv2017

Energy-momentum for a charged nonsingular black hole solution with a nonlinear mass function

The energy-momentum of a new four-dimensional, charged, spherically symmetric and nonsingular black hole solution constructed in the context of general relativity coupled to a theory of nonlinear electrodynamics is investigated, whereby the nonlinear mass function is inspired by the probability density function of the continuous logistic distribution. The energy and momentum distributions are calculated by use of the Einstein, Landau-Lifshitz, Weinberg and Møller energy-momentum complexes. In all these prescriptions it is found that the energy distribution depends on the mass $M$ and the charge $q$ of the black hole, an additional parameter $β$ coming from the gravitational background considered, and on the radial coordinate $r$. Further, the Landau-Lifshitz and Weinberg prescriptions yield the same result for the energy, while in all the aforesaid prescriptions all the momenta vanish. We also focus on the study of the limiting behavior of the energy for different values of the radial coordinate, the parameter $β$, and the charge $q$. Finally, it is pointed out that for $r\rightarrow \infty$ and $q = 0$ all the energy-momentum complexes yield the same expression for the energy distribution as in the case of the Schwarzschild black hole solution.

gr-qc↗

arXiv2016

Einstein and Møller energy-momentum complexes for a new regular black hole solution with a nonlinear electrodynamics source

A study about the energy and momentum distributions of a new charged regular black hole solution with a nonlinear electrodynamics source is presented. The energy and momentum are calculated using the Einstein and Møller energy-momentum complexes. The results show that in both pseudotensorial prescriptions the expressions for the energy of the gravitational background depend on the mass $M$ and the charge $q$ of the black hole, an additional factor $β$ coming from the spacetime metric considered, and the radial coordinate $r$, while in both prescriptions all the momenta vanish. Further, it is pointed out that in some limiting and particular cases the two complexes yield the same expression for the energy distribution as that obtained in the relevant literature for the Schwarzschild black hole solution.

gr-qc↗

arXiv2014

Energy distribution of a regular black hole solution in Einstein-nonlinear electrodynamics

In this work a study about the energy-momentum of a new four-dimensional spherically symmetric, static and charged, regular black hole solution developed in the context of general relativity coupled to nonlinear electrodynamics is presented. Asymptotically, this new black hole solution behaves as the Reissner-Nordström solution only for the particular value μ=4, where μ is a positive integer parameter appearing in the mass function of the solution. The calculations are performed by use of the Einstein, Landau-Lifshitz, Weinberg and Møller energy-momentum complexes. In all the aforesaid prescriptions, the expressions for the energy of the gravitating system considered depend on the mass M of the black hole, its charge q, a positive integer α and the radial coordinate r. In all these pseudotensorial prescriptions the momenta are found to vanish, while the Landau-Lifshitz and Weinberg prescriptions give the same result for the energy distribution. In addition, the limiting behavior of the energy for the cases r tends toward infinity, r=0 and q=0 is studied. The special case μ=4 and α=3 is also examined. We conclude that the Einstein and Møller energy-momentum complexes can be considered as the most reliable tools for the study of the energy-momentum localization of a gravitating system.

gr-qc↗

arXiv2012

Energy Distribution for Non-commutative Radiating Schwarzschild Black Holes

The aim of this article is the calculation of the energy-momentum for a non-commutative radiating Schwarzschild black hole in order to obtain the expressions for energy. We make the calculations with the Einstein and M\oller prescriptions. We show that the expressions for energy in both the prescriptions depend on the mass $M$, $θ$ parameter and radial coordinate. We make some comparisons between the results. Our results show that the Einstein prescription is a more powerful concept than the M\oller prescription.

gr-qc↗

arXiv2011

A new class of stable $(2+1)$ dimensional thin shell wormhole

Recently, Bañados, Teitelboim and Zanelli (BTZ) \cite{BTZ1992} has discovered an explicit vacuum solution of (2+1)-dimensional gravity with negative cosmological constant. It has been argued that the existence of such physical systems with an event horizon and thermodynamic properties similar to (3+1) dimensional black holes. These vacuum solutions of (2+1)-dimensional gravity are asymptotically anti-de Sitter and are known as BTZ black holes. We provide a new type of thin-shell stable wormhole from the BTZ black holes. This is the first example of stable thin shell wormhole in (2+1)-dimension. Several characteristics of this thin-shell wormhole have been discussed.

gr-qc↗

arXiv2011

On the energy of Hořava-Lifshitz black holes

In this paper we calculate the energy distribution of the Mu-in Park, Kehagias-Sfetsos (KS) and Lü, Mei and Pope (LMP) black holes in the Hořava-Lifshitz theory of gravity. These black hole solutions correspond to the standard Einstein-Hilbert action in the infrared limit. For our calculations we use the Einstein and Møller prescriptions. Various limiting and particular cases are also discussed.

gr-qc↗

arXiv2010

Classical electron model with non static conformal symmetry

Lorentz proposed a classical model of electron in which electron was assumed to have only 'electromagnetic mass'. We modeled electron as charged anisotropic perfect fluid sphere admitting non static conformal symmetry. It is noticed that the pressure and density fail to be regular at the origin but effective gravitational mass is regular everywhere and vanishes at the limit r->0 i.e. it does not have to tolerate the problem of singularity. Further, we have matched interior metric with exterior (Reissner-Nordström) metric and determine the values of the parameters k and r_0 (occurring in the solutions) in functions of mass, charge and radius of the spherically symmetric charged objects i.e. electron.

hep-th↗

arXiv2010

On the energy of charged black holes in generalized dilaton-axion gravity

In this paper we calculate the energy distribution of some charged black holes in generalized dilaton-axion gravity. The solutions correspond to charged black holes arising in a Kalb-Ramond-dilaton background and some existing non-rotating black hole solutions are recovered in special cases. We focus our study to asymptotically flat and asymptotically non-flat types of solutions and resort for this purpose to the Møller prescription. Various aspects of energy are also analyzed.

gr-qc↗

arXiv2009

Energy Distribution of a Regular Class of Exact Black Hole Solutions

In this paper we present the expressions for the energy of a regular class of exact black hole solutions of Einstein's equations coupled with a nonlinear electrodynamics source. We calculate the energy distribution using the Einstein, Weinberg and Møller prescriptions. We make a discussion of the results in function of two specific parameters, a sort of dipole and quadrupole moments of the nonlinear source $α$ and $β$, and in addition a study of some particular cases is performed.

gr-qc↗

arXiv2008

Chaplygin electron gas model

We provide a new electromagnetic mass model admitting Chaplygin gas equation of state. We investigate three specializations, the first characterized by a vanishing effective pressure, the second provided with a constant effective density and the third is described by a constant effective pressure. For these specializations two particular cases are discussed. In addition, for specialization I, case I we found isotropic coordinate as well as Kretschmann scalar, and for specialization III, case II two special scenarios have been studied.

hep-th↗

arXiv2007

Moeller's Energy-Momentum Complex for a Spacetime Geometry on a Noncommutative Curved D3-Brane

Moeller's energy-momentum complex is employed in order to determine the energy and momentum distributions for a spacetime described by a "generalized Schwarzschild" geometry in (3+1)-dimensions on a noncommutative curved D3-brane in an effective, open bosonic string theory. The geometry considered is obtained by an effective theory of gravity coupled with a nonlinear electromagnetic field and depends only on the generalized (effective) mass and charge which incorporate corrections of first order in the noncommutativity parameter.

gr-qc↗

arXiv2007

Landau-Lifshitz and Weinberg Energy-Momentum Complexes for 2+1 Dimensional Black Hole Solutions

The aim of this paper is to evaluate the energy distribution of some 2+1 black hole solutions applying the Landau-Lifshitz and Weinberg definitions. The metrics under consideration describe the charged black hole, the solution coupling to a static scalar field and the static and circularly symmetric exact solution of the Einstein-massless scalar equation. Further, we compare the expressions for energy with those obtained using the Einstein and Moller prescriptions and give a discussion of the results.

gr-qc↗

arXiv2006

Weinberg Energy-Momentum Complex for a Stringy Black Hole Solution

In our paper we compute the energy distribution of a magnetic stringy black hole solution in the Weinberg prescription. The metric under consideration describes the dual solution in the string frame that is known as the magnetic stringy black hole solution. The metric is obtained by multiplying the electric metric in the Einstein frame by a factor . The energy distribution depends on the mass M and charge Q. Also, we make a discussion of the results and we compare our result with those obtained in the Einstein and Landau and Lifshitz prescriptions and investigate the connections between the expressions of the energy obtained in these prescriptions.

gr-qc↗

arXiv2006

Energy Distribution in a Schwarzschild-like Spacetime

In this paper, utilizing Møller's energy-momentum complex, we explicitly evaluate the energy and momentum density associated with a metric describing a four-dimensional, Schwarzschild-like, spacetime derived from an effective gravity coupled with a U(1) gauge field in the context of a D3-brane dynamics in the classical regime, i.e., between the asymptotic and the Planck regime.

gr-qc↗

arXiv2005

KKW Analysis for the Dyadosphere of a Charged Black Hole

The Keski-Vakkuri, Kraus and Wilczek (KKW) analysis is used to compute the temperature and entropy in the dyadosphere of a charged black hole solution. For our purpose we choose the dyadosphere region of the Reissner-Nordstrom black hole solution. Our results show that the expressions of the temperature and entropy in the dyadosphere of this charged black hole are not the Hawking temperature and the Bekenstein-Hawking entropy, respectively.

gr-qc↗