arXiv subjects

Jishnu Suresh

Publications and source records attributed to Jishnu Suresh.

29 records · Page 2Linked to original sources

arXiv2016

Thermodynamics and Geometrothermodynamics of Charged black holes in Massive Gravity

The objective of this paper is to study the thermodynamics and thermodynamic geometry of charged de-Sitter and charged anti de-Sitter black hole solutions in massive gravity. We study the effect of curvature parameter as well as the mass of graviton in the thermodynamics of the black hole system. We further extend our studies to different topology of the space time and its effects on phase transition and thermodynamics. In addition, the phase transition structure of the black hole and its interactions are reproduced using geometrothermodynamics.

gr-qc↗

arXiv2016

Entropy spectrum of BTZ black hole in massive gravity

We study the entropy spectrum of (2+1) BTZ black holes in massive gravity models. We use the formalism proposed by Jiang and Han where black hole property of adiabaticity and the oscillating velocity of the black hole horizon are used to investigate the quantization of the entropy of such systems. We find that the entropy of the BTZ black holes in massive gravity is quantized with equally spaced spectra.

gr-qc↗

arXiv2015

Thermodynamics of Charged Lovelock - AdS Black Holes

We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.

gr-qc↗

arXiv2015

Entropy spectrum of (1+1) dimensional stringy black holes

We explore the entropy spectrum of $(1+1)$ dimensional dilatonic stringy black holes via the adiabatic invariant integral method and the Bohr-Sommerfeld quantization rule. It is found that the corresponding spectrum depends on black hole parameters like charge, ADM mass and more interestingly on the dilatonic field. We calculate the entropy of the present black hole system via the Euclidean treatment of quantum gravity and study the thermodynamics of the black hole and find that the system does not undergo any phase transition.

gr-qc↗

arXiv2014

A unified thermodynamic picture of Hořava-Lifshitz black hole in arbitrary space time

In this paper, we analyze the complete thermodynamic and phase transition phenomena of a black hole solution in Hořava-Lifshitz gravity in arbitrary space time. Nature of phase transition is studied using geometrothermodynamic and Ehrenfest's scheme of standard thermodynamics. We analytically check the Ehrenfest's equations near the critical point, which is the point of divergence in the heat capacity. Our analysis revels that this black hole exhibits a second order phase transition.

gr-qc↗

arXiv2014

Phase transitions and Geometrothermodynamics of Regular black holes

In this paper we study the thermodynamics and state space geometry of regular black hole solutions such as Bardeen black hole, Ayón-Beato and García black hole, Hayward black hole and Berej-Matyjasek-Trynieki-Wornowicz black hole. We find that all these black holes show second order thermodynamic phase transitions(SOTPT) by observing discontinuities in heat capacity-entropy graphs as well as the cusp type double point in free energy-temperature graph. Using the formulation of geometrothermodynamics we again find the singularities in the heat capacity of the black holes by calculating the curvature scalar of the Legendre invariant metric.

gr-qc↗

arXiv2014

Thermodynamic Geometry of Reissener-Nordström-de Sitter black hole and its extremal case

We study the thermodynamics and the different thermodynamic geometric methods of Reissener-Nordström-de Sitter black hole and its extremal case, which is similar to the de Sitter black hole coupled to a scalar field, rather called an MTZ black hole. While studying the thermodynamics of the systems, we could find some abnormalities. In both cases, the thermodynamic geometric methods could give the correct explanation for the all abnormal thermodynamic behaviors in the system.

gr-qc↗

arXiv2014

Thermodynamics and Thermodynamic geometry of Park black hole

We study the thermodynamics and thermodynamic geometry of Park black hole in Hořava gravity. By incorporating the ideas of differential geometry, we have investigated the thermodynamics using Weinhold geometry and Ruppeiner geometry. We have also analyzed it in the context of newly developed geometrothermodynamics(GTD). Divergence of specific heat is associated with the second order phase transition of black hole. Here in the context of Park black hole, both Weinhold's metric and Ruppeiner's metric well explain this phase transition. But these explanations depend on the choice of potential. Hence the Legendre invariant GTD is used, and with the true singularities in the curvature scalar, GTD well explain the second order phase transition. All these methods together give an exact idea of all the behaviors of the Park black hole thermodynamics.

gr-qc↗

arXiv2013

Thermodynamics and Quasinormal modes of Park black hole in Hořava gravity

We study the quasinormal modes of the massless scalar field of Park black hole in the Hořava gravity using the third order WKB approximation method and found that black hole is stable against these perturbation. We compare and discuss the results with that of Schwarzschild-de Sitter black hole. Thermodynamic properties of Park black hole are investigated and the thermodynamic behavior of upper mass bound is also studied.

gr-qc↗

arXiv2013

Area spectrum and thermodynamics of KS black holes in Hořava gravity

We investigate the area spectrum of Kehagias-Sfetsos black hole in Hořava-Lifshitz gravity via modified adiabatic invariant $I=\oint p_i d q_i$ and Bohr-Sommerfeld quantization rule. We find that the area spectrum is equally spaced with a spacing of $ ΔA=4 πl_p ^2$. We have also studied the thermodynamic behavior of KS black hole by deriving different thermodynamic quantities.

gr-qc↗

arXiv2012

Modified holographic Ricci dark energy model and statefinder diagnosis in flat universe

Evolution of the universe with modified holographic Ricci dark energy model is considered. Dependency of the equation of state parameter and deceleration parameter on the redshift and model parameters are obtained. It is shown that the density evolution of both non-relativistic matter and dark energy are the same until recent times. The evolutionary trajectories of the model for different model parameters are obtained in the statefinder planes, r-s and r-q planes. The present statefinder parameters are obtained for different model parameter values, using that the model is differentiated from other standard models like $Λ$CDM model etc. We have also shown that the evolutionary trajectories are depending on the model parameters, and at past times the dark energy is behaving like cold dark matter, with equation of state equal to zero.

astro-ph.CO↗