4
4.0
Jun 29, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; S. Panahiyan
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Violation of Lorentz invariancy in the high energy quantum gravity motivates one to consider an energy dependent spacetime with massive deformation of standard general relativity. In this paper, we take into account an energy dependent metric in the context of a massive gravity model to obtain exact solutions. We investigate the geometry of black hole solutions and also calculate the conserved and thermodynamic quantities, which are fully reproduced by the analysis performed with the standard...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1602.01832
4
4.0
Jun 29, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; S. Panahiyan
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Motivated by recent developments of BTZ black holes and interesting results of massive gravity, we investigate massive BTZ black holes in the presence of Maxwell and Born-Infeld (BI) electrodynamics. We study geometrical properties such as type of singularity and asymptotical behavior as well as thermodynamic structure of the solutions through canonical ensemble. We show that despite the existence of massive term, obtained solutions are asymptotically (a)dS and have a curvature singularity at...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1604.00370
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3.0
Jun 30, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; R. Saffari
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In this paper, we consider Einstein gravity in the presence of a class of nonlinear electrodynamics, called power Maxwell invariant (PMI). We take into account $(2+1)$-dimensional spacetime in Einstein-PMI gravity and obtain its black hole solutions. Then, we regard pure $F(R)$ gravity as well as $F(R)$-conformally invariant Maxwell theory to obtain exact solutions of the field equations with black hole interpretation. Finally, we investigate the conserved and thermodynamic quantities and...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1408.5570
4
4.0
Jun 28, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; S. Panahiyan
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Motivated by gauge/gravity group in the low energy effective theory of the heterotic string theory and novel aspects of massive gravity in the context of lattice physics, the minimal coupling of Gauss-Bonnet-massive gravity with Born-Infeld electrodynamics is considered. At first, the metric function is calculated and then the geometrical properties of the solutions are investigated. It is found that there is an essential singularity at the origin and the intrinsic curvature is regular...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1510.00108
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8.0
Jun 28, 2018
06/18
by
S. H. Hendi; S. Panahiyan; B. Eslam Panah
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Motivated by high interest in the close relation between string theory and black hole solutions, in this paper, we take into account the Einstein-Gauss-Bonnet Lagrangian in the context of massive gravity. We examine the possibility of black hole in this regard, and discuss the types of horizons. Next, we calculate conserved and thermodynamic quantities and check the validity of the first law of thermodynamics. In addition, we investigate the stability of these black holes in context of...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1507.06563
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7.0
Jun 30, 2018
06/18
by
S. H. Hendi; S. Panahiyan; B. Eslam Panah
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In this paper, we take into account the black hole solutions of Einstein gravity with logarithmic and exponential forms of nonlinear electrodynamics. We consider $\Lambda$ as a dynamical pressure to study the analogy of the black holes with the Van der Waals system. We plot P-v, T-v and G-T diagrams and investigate the phase transition of adS black holes in the canonical ensemble. We study the nonlinearity effects of electrodynamics and see how the power of nonlinearity affects critical...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1410.0352
7
7.0
Jun 28, 2018
06/18
by
S. H. Hendi; S. Panahiyan; B. Eslam Panah
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eye 7
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In this paper, we consider Lovelock gravity in presence of two Born-Infeld types of nonlinear electrodynamics and study their thermodynamical behavior. We extend the phase space by considering cosmological constant as a thermodynamical pressure. We obtain critical values of pressure, volume and temperature and investigate the effects of both the Lovelock gravity and the nonlinear electrodynamics on these values. We plot $P-v$, $T-v$ and $G-T$ diagrams to study the phase transition of these...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1511.00656
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24
Jun 26, 2018
06/18
by
G. H. Bordbar; S. H. Hendi; B. Eslam Panah
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Regarding a $d-$dimensional spherically symmetric line element in the context of Einstein-$\Lambda$ gravity, the hydrostatic equilibrium equation of stars is obtained. Then, by using the lowest order constrained variational (LOCV) method with the AV$18$ potential and employing microscopic many body calculations in the modern equation of state, the structure properties of neutron stars are investigated. Regardless of cosmological point of view and considering arbitrary positive and negative...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1502.02929
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40
Sep 18, 2013
09/13
by
S. H. Hendi; B. Eslam Panah; S. M. Mousavi
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In this paper we obtain topological static solutions of some kind of pure $F(R)$ gravity. The present solutions are two kind: first type is uncharged solution which corresponds with the topological (a)dS Schwarzschild solution and second type has electric charge and is equivalent to the Einstein-$\Lambda$-conformally invariant Maxwell solution. In other word, starting from pure gravity leads to (charged) Einstein-$\Lambda$ solutions which we interpreted them as (charged) (a)dS black hole...
Source: http://arxiv.org/abs/1102.0089v4
5
5.0
Jun 28, 2018
06/18
by
S. H. Hendi; S. Panahiyan; B. Eslam Panah; Z. Armanfard
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In this paper, we take into account black hole solutions of Brans-Dicke-Maxwell theory and investigate their stability and phase transition points. We apply the concept of geometry in thermodynamics to obtain phase transition points and compare its results with those, calculated in canonical ensemble through heat capacity. We show that these black holes enjoy second order phase transitions. We also show that there is a lower bound for the horizon radius of physical charged black holes in...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1511.00598
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7.0
Jun 29, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; S. Panahiyan; M. Momennia
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Motivated by UV completion of general relativity with a modification of a geometry at high energy scale, it is expected to have an energy dependent geometry. In this paper, we introduce charged black hole solutions with power Maxwell invariant source in the context of gravity's rainbow. In addition, we investigate two classes of $F(R)$ gravity's rainbow solutions. At first, we study energy dependent $F(R)$ gravity without energy momentum tensor, and then we obtain $F(R)$ gravity's rainbow in...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1607.03383
7
7.0
Jun 28, 2018
06/18
by
S. H. Hendi; S. Panahiyan; B. Eslam Panah; M. Momennia
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eye 7
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Motivated by providing preliminary steps to understand the conception of quantum gravity, in this paper, we study the phase structure of a semiclassical gravitational system. We investigate the stability conditions and phase transition of charged black holes in massive gravity via canonical and geometrical thermodynamic approaches. We point out the effects of massive parameter on stability conditions of these black holes and show how massive coefficients affect the phase transition points of...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1506.07262
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9.0
Jun 28, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; M. Momennia; S. Panahiyan
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eye 9
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Inspired by large applications of topological defects in describing different phenomena in physics, and considering the importance of three dimensional solutions in AdS/CFT correspondence, in this paper we obtain magnetic anti-de Sitter solutions of nonlinear electromagnetic fields. We take into account three classes of nonlinear electrodynamic models; first two classes are the well-known BornInfeld like models including logarithmic and exponential forms and third class is known as the power...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1509.03081
7
7.0
Jun 29, 2018
06/18
by
S. H. Hendi; S. Panahiyan; S. Upadhyay; B. Eslam Panah
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eye 7
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BTZ black holes are excellent laboratories for studying black hole thermodynamics which is a bridge between classical general relativity and quantum nature of gravitation. In addition, three-dimensional gravity could have equipped us for exploring some of the ideas behind the two dimensional conformal field theory based on the $AdS_{3}/CFT_{2}$. Considering the significant interests in these regards, we examine charged BTZ black holes. We consider the system contains massive gravity with energy...
Topics: High Energy Physics - Theory, General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1611.02937
7
7.0
Jun 30, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; S. Panahiyan; A. Sheykhi
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eye 7
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Motivated by low energy effective action of string theory and large applications of BTZ black holes, we will consider minimal coupling between dilaton and nonlinear electromagnetic fields in three dimensions. The main goal is studying thermodynamical structure of black holes in this set up. Temperature and heat capacity of these black holes are investigated and a picture regarding their phase transitions is given. In addition, the role and importance of studying the mass of black holes is...
Topic: General Relativity and Quantum Cosmology
Source: http://arxiv.org/abs/1703.03403
4
4.0
Jun 28, 2018
06/18
by
S. H. Hendi; S. Panahiyan; B. Eslam Panah; M. Momennia
texts
eye 4
favorite 0
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Motivated by the violation of Lorentz invariancy in quantum gravity, we study black hole solutions in gravity's rainbow in context of Einstein gravity coupled with various models of nonlinear electrodynamics. We regard an energy dependent spacetime and obtain related metric functions and electric fields. We show that there is an essential singularity at the origin which is covered with an event horizon. We also compute the conserved and thermodynamical quantities and examine the validity of the...
Topics: General Physics, Physics
Source: http://arxiv.org/abs/1512.05192
4
4.0
Jun 30, 2018
06/18
by
S. H. Hendi; B. Eslam Panah; S. Panahiyan; M. Momennia
texts
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The Noble Prize in physics 2016 motivates one to study different aspects of topological properties and topological defects as their related objects. Considering the significant role of the topological defects (especially magnetic strings) in cosmology, here, we will investigate three dimensional horizonless magnetic solutions in the presence of two generalizations: massive gravity and nonlinear electromagnetic field. The effects of these two generalizations on properties of the solutions and...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1704.00996
3
3.0
Jun 28, 2018
06/18
by
S. H. Hendi; A. Sheykhi; S. Panahiyan; B. Eslam Panah
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eye 3
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In this paper, we consider a linearly charged dilatonic black holes and study their thermodynamical behavior in the context of phase transition and thermodynamic geometry. We show that, depending on the values of the parameters, these type of black holes may enjoy two types of phase transition. We also find that there are three critical behaviors near the critical points for these black holes; nonphysical unstable to physical stable, large to small, and small to large black holes phase...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1509.08593
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12
Jun 28, 2018
06/18
by
S. H. Hendi; Mir Faizal; B. Eslam Panah; S. Panahiyan
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eye 12
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In this paper, we present charged dilatonic black holes in gravity's rainbow. We study geometric and thermodynamic properties of black hole solutions. We also investigate the effects of rainbow functions on different thermodynamic quantities for these charged black holes in dilatonic gravity's rainbow. Then, we demonstrate that first law of thermodynamics is valid for these solutions. After that, we investigate thermal stability of the solutions using canonical ensemble and analyze the effects...
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1508.00234
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5.0
Jun 30, 2018
06/18
by
S. H. Hendi; R. B. Mann; S. Panahiyan; B. Eslam Panah
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Motivated by recent developments in black hole thermodynamics, we investigate van der Waals phase transitions of charged black holes in massive gravity. We find that massive gravity theories can exhibit strikingly different thermodynamic behaviour compared to that of Einstein gravity, and that the mass of the graviton can generate a range of new phase transitions for topological black holes that are otherwise forbidden.
Topics: General Relativity and Quantum Cosmology, High Energy Physics - Theory
Source: http://arxiv.org/abs/1702.00432
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9.0
Jun 28, 2018
06/18
by
S. H. Hendi; G. H. Bordbar; B. Eslam Panah; S. Panahiyan
texts
eye 9
favorite 0
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In this paper, we consider a spherical symmetric metric to extract the hydrostatic equilibrium equation of stars in $(3+1)-$dimensional gravity's rainbow in the presence of cosmological constant. Then, we generalize the hydrostatic equilibrium equation to $d$-dimensions and obtain the hydrostatic equilibrium equation for this gravity. Also, we obtain the maximum mass of neutron star using the modern equations of state of neutron star matter derived from the microscopic calculations. It is...
Topics: High Energy Astrophysical Phenomena, Astrophysics, General Relativity and Quantum Cosmology, High...
Source: http://arxiv.org/abs/1509.05145
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93
Sep 22, 2013
09/13
by
S. H. Hendi; R. B. Mann; N. Riazi; B. Eslam Panah
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eye 93
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We consider a model of $F(R)$ gravity in which exponential and power corrections to Einstein-$\Lambda$ gravity are included. We show that this model has 4-dimensional Eguchi-Hanson type instanton solutions in Euclidean space. We then seek solutions to the five dimensional equations for which space-time contains a hypersurface corresponding to the Eguchi-Hanson space. We obtain analytic solutions of the $F(R)$ gravitational field equations, and by assuming certain relationships between the model...
Source: http://arxiv.org/abs/1210.3629v1
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Jun 27, 2018
06/18
by
S. H. Hendi; G. H. Bordbar; B. Eslam Panah; M. Najafi
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eye 13
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In this paper, we present a new hydrostatic equilibrium equation related to dilaton gravity. We consider a spherical symmetric metric to obtain the hydrostatic equilibrium equation of stars in $4$-dimensions, and generalize TOV equation to the case of regarding a dilaton field. Then, we calculate the structure properties of neutron star using our obtained hydrostatic equilibrium equation employing the modern equations of state of neutron star matter derived from microscopic calculations. We...
Topics: General Relativity and Quantum Cosmology, High Energy Astrophysical Phenomena, Astrophysics, High...
Source: http://arxiv.org/abs/1503.01011
