arXiv subjects
Publications and source records attributed to Prince A. Ganai.
In this paper, we study Hawking radiation in Jackiw-Teitelboim gravity for minimally coupled massless and massive scalar fields. We employ a holography-inspired technique to derive the Bogoliubov coefficients. We consider both black holes in equilibrium and black holes attached to a bath. In the latter case, we compute semiclassical deviations from the thermal spectrum.
We exploit a new theory of gravity proposed by Finzi, which gives stronger interaction at large scales, to study the thermodynamic description of galaxy clusters. We employ a statistical model to deduce various thermodynamics equations of state. In addition, we analyze the behavior of clustering parameter in comparison to its standard (Newtonian) counterpart. The general distribution function and its behavior with varying strength of clustering parameter are also studied. The possibility of phase transition is investigated and it is observed that a phase transition is possible though hierarchically. We also analyze the model by comparing the results with data available through SDSS-III, and obtain the parameters involved.
We discuss the galaxy clustering based on thermodynamics and statistical mechanics in the expanding universe in a modified theory of gravity. The modified general relativity (MGR) is developed using the regular line element field to construct a symmetric tensor that represents the energy momentum of the gravitational field. This in turn provides a modified gravitational potential with terms that represent dark matter and dark energy effects without actually invoking the two. Based on the modified gravitational potential we calculate the distribution function of the galaxies. We also calculate various thermodynamic equations of state. We make a data analysis of the data obtained through the SDSS-III survey and check the feasibility of the theoretical model of probability distribution of galaxies in the universe.
We examine the effect of addition of graviton mass on the efficiency of a regular charged black hole (RCB). In doing so, we make few comments on the critical behaviour of the system and calculate the relevant thermodynamic quantities such as entropy, Hawkings temperature and heat capacity. We confirm that graviton mass has a positive effect on the efficacy of such a heat engine under consideration.
We examine the thermodynamics of a regular charged black hole (RCB) added with corrections due to massive gravity and thermal fluctuations at quantum level. We then derive the expressions for all the relevant thermodynamic quantities such as entropy, Hawkings temperature, internal energy, Gibbs free energy, corrected to first order. We also briefly discuss the stability of such a system with the help of quantities like specific heat and thermodynamic pressure, along with this we present their comparative study with the corresponding original values.
We developed the functional form of the two-point correlation function under the approximation of fixed particle number density n(bar). We solved the quasi-linear partial differential equation (PDE) through the method of characteristics to obtain the parametric solution for the canonical ensemble. We attempted many functional forms and concluded that the functional form should be such that the two-point correlation function should go to zero as the value of system temperature increases or the separation between the galaxies becomes large. Also, we studied the graphical behavior of the developed two-point correlation function for large values of temperature T and spatial separation r. The behavior of the two-point function was also studied from the temperature measurement of clusters in the redshift range of 0.023 to 0.546.
We study the effect of nonfactorizable background geometry on the thermodynamics of the clustering of galaxies. A canonical partition function is derived for the gravitating system of galaxies treated as point particles contained in cells of appropriate dimensions. Various thermodynamic equations of state, like Helmholtz free energy and entropy, among others, are also obtained. We also estimate the effect of the corrected Newton law on the distribution function of galaxies. Remarkably, the effect of the modified Newton law is seen only in the clustering parameter while the standard structure of the equations is preserved. A comparison of the modified clustering parameter with that of the original clustering parameter is made to visualize the effect of the correction on the time scale of clustering. The possibility of system symmetry breaking is also analyzed by investigating the behavior of the specific heat with increasing system temperature.
We present the thermodynamics of a charged and rotating BTZ black holes here. In particular, we derive expressions for various macroscopic thermal quantities such as entropy, Hawking temperature, Helmholtz free energy, internal energy, enthalpy, Gibbs free energy, and specific heat. To study the effects of small statistical thermal fluctuations around the equilibrium on thermodynamics, we calculated the leading-order corrections to the various thermodynamical potentials of charged and rotating BTZ black hole and do comparative analysis for the fixed values of charge and angular momentum.
We study the thermodynamics of galaxy clusters in a modified Newtonian potential motivated by a general solution to Newton's "sphere-point" equivalence theorem. We obtain the $N$ particle partition function by evaluating the configurational integral while accounting for the extended nature of galaxies (via the inclusion of the softening parameter $ε$ into the potential energy function). This softening parameter takes care of the galaxy-halos whose effect on structuring the shape of the galactic disc has been found recently. The spatial distribution of the particles (galaxies) is also studied in this framework. A comparison of the new clustering parameter $b_+$ to the original clustering parameters is presented in order to visualize the effect of the modified gravity. We also discuss the possibility of system symmetry breaking via the behavior of the specific heat as a function of temperature.
In this paper, we discuss remnants of the Bardeen regular black hole motivated by using the concept of thermal fluctuations. First, we derive the equilibrium values of various thermodynamic quantities like entropy, Hawking temperature, pressure, internal energy, Helmholtz free energy and Gibbs free energy in the non-extended phase space. We then discuss geometrothermodynamics (GTD) of Bardeen black hole to study its stability. Next, we estimate the size of black hole remnant in terms of some known parameters of the black hole solution. Motivated by the fact that estimation of size, characteristics and stability of remnants of black holes could further increase our understanding of binary collisions, information loss paradox and dark energy, the black hole remnant, which gives an idea about stable mass left over after evaporation of black hole, is seen to owe its presence due to thermal fluctuations. We see that the thermal fluctuations bring an overall increase in entropy curve. However, in presence of thermal fluctuations, a positive kink, which signifies a maximum increase in the value of entropy, occurs at a certain value of horizon, which is exactly equal to the remnant radius. We observe that the thermal fluctuations, which are characteristics of quantum gravity, lead to stable values of thermodynamic quantities near the remnant radius. In presence of thermal fluctuations, we then derive various corrected thermodynamic potentials and also discuss the validity of first law of black hole thermodynamics for Bardeen black hole.
We estimate galaxy clustering under a modified gravitational potential. In particular, the modifications in gravitational potential energy occur due to a power-law and cosmological constant terms. We derive a canonical partition function for the system of galaxies interacting under such a modified gravitational potential. Moreover, we compute various thermodynamical equation of states for the system. We do comparative analysis in order to emphasize the effect of corrections on thermodynamics of the system. Interestingly, the modifications in thermodynamical quantities are embedded in clustering parameter only.
In this paper, we discuss remnants and quantum gravity effects on thermodynamics of new kind of regular black hole known as Culetu black hole. The black hole results in coupling of gravity to non linear electrodynamic source. We first derive various thermodynamic quantities of interest. We then discuss in detail the existence and stability of remnants. The stability of remnants is analyzed in presence of thermal fluctuations and we observe that thermal fluctuations tend to increase the entropy at the horizon radius which is exactly the remnant radius. We then investigate non perturbative quantum gravity effects on the thermodynamics of Culetu black hole up to leading order terms.
In this paper, we study the quantum corrected thermodynamics of a class of black holes generated by self-gravitating Skyrmion models. One such black hole solution is Einstein-Skrymion black hole. We first compute the ADM mass of Einstein-Skyrmion black hole using on-shell Hamiltonian formalism present already in the literature. We then consider non-extended phase space thermodynamics and derive expressions for various thermodynamic quantities like the Hawking temperature, entropy, pressure, Gibbs free energy, and heat capacity. Next, we study the effect of quantum corrections on the thermodynamics of the Einstein-Skyrmion black hole. We observe that apart from leading to stability, the quantum correction induce an AdS (anti-de sitter) to dS (de Sitter) phase transition in Einstein-Skrymion black hole. Treating cosmological constant as the pressure, we determine the $P-V$ criticality of the Einstein-Skrymion black hole and observe that the $P-V$ criticality depends on model parameters $λ$ and $K$. The study of $P-V$ criticality done here could help to estimate the experimental bound on the values of parameters $λ$ and $K$.
In this paper, we discuss the effect of small statistical thermal fluctuations around the equilibrium on the thermodynamics of small non-rotating BTZ black hole. This is done by evaluating the leading-order corrections to the thermodynamical equation of states, namely, entropy, free energy, internal energy, pressure, enthalpy, Gibbs free energy and specific heat quantitatively. In order to analyze the effect of perturbations on the thermodynamics, we plot various graphs and compare corrected and non-corrected thermodynamic quantities with respect to event horizon radius of non-rotating BTZ black hole. We also derive the first-order corrections to isothermal compressibility.
We develop a BRST symmetric gaugeon formalism for the Abelian rank-2 antisymmetric tensor field in the Lorentz breaking framework. The Lorentz breaking is achieved here by considering a proper subgroup of Lorentz group together with translation. In this scenario, the gaugeon fields together with the standard fields of the Abelian rank-2 antisymmetric tensor theory get mass. In order to develop the gaugeon formulation for this theory in VSR, we first introduce a set of dipole vector fields as a quantum gauge freedom to the action. In order to quantize the dipole vector fields, the VSR-modified gauge-fixing and corresponding ghost action are constructed as the classical action is invariant under a VSR-modified gauge transformation. Further, we present a Type I gaugeon formalism for the Abelian rank-2 antisymmetric tensor field theory in VSR. The gauge structures of Fock space constructed with the help of BRST charges are also discussed.
In this paper, we will analyse a supersymmetric field theory deformed by generalized uncertainty principle and Lifshitz scaling. It will be observed that this deformed supersymmetric field theory contains non-local fractional derivative terms. In order to construct such deformed N=1 supersymmetric theory, a harmonic extension of functions will be used. However, the supersymmetry will be only preserved for a free theory and will be broken by the inclusion of interaction terms.
Very special relativity (VSR) keeps the main features of special relativity but breaks rotational invariance due to an intrinsic preferred direction. We study the VSR modified extended BRST and anti-BRST symmetry of the Batalin-Vilkovisky (BV) actions corresponding to the $p=1,2,3$-form gauge theories. Within VSR framework, we discuss the extended BRST invariant and extended BRST and anti-BRST invariant superspace formulations for these BV actions. Here we observe that the VSR modified extended BRST invariant BV actions corresponding to the $p=1,2,3$-form gauge theories can be written manifestly covariant manner in a superspace with one Grassmann coordinate. Moreover, two Grassmann coordinates are required to describe the VSR modified extended BRST and extended anti-BRST invariant BV actions in a superspace. These results are consistent with the Lorentz invariant (special relativity) formulation.
In this paper, we consider a $D$-dimensional massive Thirring model with ($2<D<4$). We derive an extended BRST symmetry of the theory with finite field-dependent parameter. Further we compute the Jacobian of functional measure under such an extended transformation. Remarkably, we find that such Jacobian extends the BRST exact part of the action which leads to a mapping between different gauges. We illustrate this with the help of Lorentz and $R_ξ$ gauges. We also discuss the results in Batalin-Vilkovisky framework.