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This study derives a novel family of charged black hole solutions featuring short- and long-range modifications. These ones are achieved through a Yukawa-like gravitational potential modification and a nonsingular electric potential incorporation. The short-range corrections encode quantum gravity effects, while the long-range adjustments simulate gravitational effects akin to those attributed to dark matter. Our investigation reveals that the total mass of the black hole undergoes corrections owing to the apparent presence of dark matter mass and the self-adjusted electric charge mass. Two distinct solutions are discussed: a regular black hole solution characterizing small black holes, where quantum effects play a crucial role, and a second solution portraying large black holes at considerable distances, where the significance of Yukawa corrections comes into play. Notably, these long-range corrections contribute to an increase in the total mass and hold particular interest as they can emulate the role of dark matter. Finally, we explore the phenomenological aspects of the black hole. Specifically, we examine the influence of electric charge and Yukawa parameters on thermodynamic quantities, the quasinormal modes for the charged scalar perturbations as well as for the vector perturbations, analysis of the geodesics of light/massive particles, and the accretion of matter onto the charged black hole solution., Comment: 19 pages in two column, 18 figures and 2 tables

In this study, we explore the properties of a non-rotating black hole in the Einstein-Maxwell-scalar (EMS) theory and investigate the luminosity of the accretion disk surrounding it. We determine all the orbital parameters of particles in the accretion disk, including the radius of the innermost stable circular orbit (ISCO) with angular velocity, angular momentum, and energy. Further, we study the radiative efficiency for different values of black hole parameters. Finally, we analyze the flux, differential luminosity, and temperature of the accretion disk.

In this paper we study the accretion of matter onto the black holes and the shadow images obtained by an infalling accretion flow of gas in a theory of massive gravity (MG) with a spontaneously breaking Lorentz symmetry. This black hole solution is characterized by mass $M$, scalar charge $S$ and the parameter $\lambda$. In order to extract the astrophysical results of our analyses, firstly, we have assumed a specific range for the parameter $\lambda$ to constrain the scalar charge $S$ using the EHT result. To this end, we have studied the effect of the scalar charge on the intensity of the electromagnetic radiation from the black hole. Moreover, we investigate the behavior of polytropic as well as the isothermal fluid flow onto massive gravity black hole and notice that accretion starts from supersonic/subsonic flow, passes through the critical point using particular model parameter and ends near the horizon. We also analyzed the mass accretion rate in the presence of various fluids which indicates important signatures. We also elaborate on the possibility to analyze the phase transition and the stability of the black hole using the shadow formalism., Comment: 14 pages, 24 figures, the manuscript is accepted for publication in Physical Review D

The baryogenesis presents the theoretical mechanism that describes the matter-antimatter asymmetry in the history of early universe. In this work, we investigate the gravitational baryogenesis phenomena in the frameworks of $f(T, T_G)$ (where $T$ and $T_G$ are the torsion scalar and teleparallel equivalent to the Gauss-Bonnet term respectively) and $f(T, B)$ (where $B$ denotes the boundary term between torsion and Ricci scalar) gravities. For $f(T,T_G)$-gravity, we consider two generic power law models while logarithmic and general Taylor expansion models for $f(T,B)$-gravity. We consider power law scale factor for each model and compute baryon to entropy ratio by assuming that the universe filled by perfect fluid and dark energy. We find generalized baryogenesis interaction which is proportional to $\partial_\mu f(T+T_G)$ and $\partial_\mu f(T+B)$ for both theories of gravity. We compare our results against current astrophysical data of baryon to entropy ratio, which indicates excellent consistency with observational bounds (i.e., $\frac{\eta_B}{S} = 9.42 \times 10^{-11}$)., Comment: 24 pages, 08 Figures, Accepted in Physics of Dark Universe

Quantum fluctuation consequences have significant role in high-energy physics. These fluctuation often regarded as a correction of the infrared (IR) limit. Such correction contribute to the high-energy limit of thermodynamical quantities and the stability conditions of black holes. In this work, we analyze the thermal stability of black holes in the presence of thermal fluctuations. We consider AdS black hole in Born-Infeld massive gravity with non-abelian hair and the charged AdS black hole with a global monopole. We develop many thermodynamical quantities such as entropy, temperature, pressure, heat capacity of a system at constant volume and pressure, ratio between the heat capacities at constant pressure and volume, Gibbs free energy and Helmholtz free energy for both black holes. The critical behavior and phase transitions of black holes are also presented. We also observe the local and global stability of black holes in the grand canonical ensemble and canonical ensemble for the specific values of different parameters, such as, symmetry breaking parameter $\eta$, massive parameter $m$ and non-abelian hair $\nu$., Comment: 29 pages, 26 figures, Accepted in CQG for publication

In this paper, we reconstruct various solutions for the accelerated universe in the Einstein-Aether theory of gravity. For this purpose, we obtain the effective density and pressure for Einstein-Aether theory. We reconstruct the Einstein-Aether models by comparing its energy density with various newly proposed holographic dark energy models such as Tsallis, R$\acute{e}$nyi and Sharma-Mittal. For this reconstruction, we use two forms of scale factor, power-law and exponential forms. The cosmological analysis of underlying scenario has been done by exploring different cosmological parameters. This includes equation of state parameter, squared speed of sound and evolutionary equation of state parameter via graphical representation. We obtain some favorable results for some values of model parameters., Comment: 32 pages, 18 figures, version accepted for publication in Symmetry

Recently, Tsallis, R\'{e}nyi and Sharma-Mitall and entropies have widely been used to study the gravitational and cosmological setups. We consider a flat FRW universe with linear interaction between dark energy and dark matter. We discuss the dark energy models using Tsallis, R\'{e}nyi and Sharma-Mitall entropies in the framework of Chern-Simons modified gravity. We explore various cosmological parameters (equation of state parameter, squared sound of speed ) and cosmological plane ($\omega_{d}-\omega_{d}'$, where $\omega_{d}'$, is the evolutionary equation of state parameter). It is observed that the equation of state parameter gives quintessence-like nature of the universe in most of the cases. Also, the squared speed of sound shows stability of the models for Tsallis, R\'{e}nyi dark energy model while unstable behavior for Sharma-Mitall dark energy model. The $\omega_{d}-\omega_{d}'$ plane represents the thawing region for all dark energy models., Comment: 19 pages, 9 figures, to appear in AHEP

For analyzing the thermodynamical behavior of two well-known black holes such as RN-AdS black hole with global monopole and $f(R)$ black hole, we consider the higher order logarithmic corrected entropy. We develop various thermodynamical properties such as, entropy, specific heats, pressure, Gibb's and Helmhotz free energies for both black holes in the presence of corrected entropy. The versatile study on the stability of black holes is being made by using various frameworks such as the ratio of heat capacities ($\gamma$), grand canonical and canonical ensembles, and phase transition in view of higher order logarithmic corrected entropy. It is observed that both black holes exhibit more stability (locally as well as globally) for growing values of cosmological constant and higher order correction terms., Comment: 23 pages, 10 figures, accepted for publication by Canadian Journal of Physics. arXiv admin note: text overlap with arXiv:1701.08650 by other authors

We explore the thermodynamic analysis at the apparent horizon in the framework of Rastall theory of gravity. We take different entropies such as the Bakenstein, logarithmic corrected, power law corrected, and the Renyi entropies. We investigate the first law and generalized second law of thermodynamics analytically for these entropies which hold under certain conditions. Furthermore, the behavior of the total entropy in each case is analyzed. As a result, it is implied that the generalized second law of thermodynamics is satisfied. We also check whether the thermodynamic equilibrium condition for these entropies is met at the present horizon., Comment: 23 pages, 12 figures, version accepted for publication in European Physical Journal C

We consider the particle creation scenario in the dynamical Chern-Simons modified gravity in the presence of perfect fluid equation of state $p=(\gamma-1)\rho$. By assuming various modified entropies (Bekenstein, logarithmic, power law correction and Reyni), we investigate the first law of thermodynamics and generalized second law of thermodynamics on the apparent horizon. In the presence of particle creation rate, we discuss the generalized second law of thermodynamics and thermal equilibrium condition. It is found that thermodynamic laws and equilibrium condition remain valid under certain conditions of parameters., Comment: 32 pages, 12 figures, AHEP accepted. arXiv admin note: text overlap with arXiv:1801.09999; text overlap with arXiv:1604.00899, arXiv:0811.4477 by other authors

In this paper, we study the dynamical instability of a collapsing object in the framework of generalized teleparallel gravity. We assume a cylindrical object with a specific matter distribution. This distribution contains energy density, isotropic pressure component with heat conduction. We take oscillating states scheme up to first order to check the instable behavior of the object. We construct a general collapse equation for underlying case with non-diagonal tetrad depending on the matter, metric functions, heat conducting term and torsional terms. The Harrison-Wheeler equation of state which contains adiabatic index is used to explore the dynamical instability ranges for Newtonian and post-Newtonian constraints. These ranges depend on perturbed part of metric coefficients, matter parts and torsion., Comment: 21 pages, Accepted for publication in AHEP

We investigate the validity of generalized second law of thermodynamics of a physical system comprising of newly proposed dark energy model called Ricci Gauss-Bonnet and cold dark matter enveloped by apparent horizon and event horizon in flat Friedmann-Robertson-Walker (FRW) universe. For this purpose, Bekenstein entropy, Renyi, logarithmic and power law entropic corrections are used. It is found that this law exhibits the validity on both apparent and event horizons except for the case of logarithmic entropic correction at apparent horizon. Also, we check the thermodynamical equilibrium condition for all cases of entropy and found its vitality in all cases of entropy., Comment: 23 pages, 16 figures

In this paper, we discuss the thermodynamical analysis for gravitationally induced particle creation scenario in the framework of DGP braneworld model. For this purpose, we consider apparent horizon as the boundary of the universe. We take three types of entropy such as Bakenstein entropy, logarithmic corrected entropy and power law corrected entropy with ordinary creation rate $\Gamma$. We analyze the first law and generalized second law of thermodynamics analytically for these entropies which hold under some constraints. The behavior of total entropy in each case is also discussed which implies the validity of generalized second law of thermodynamics. Also, we check the thermodynamical equilibrium condition for two phases of creation rate, that is constant and variable $\Gamma$ and found its validity in all cases of entropy., Comment: 27 pages, 9 figures

In the present work, we study the consequences of considering a recently proposed polynomial inflationary potential in the context of the generalized, modified, and generalized cosmic Chaplygin gas models. In addition, we consider dissipative effects by coupling the inflation field to radiation, i.e., the inflationary dynamics is studied in the warm inflation scenario. We take into account a general parametrization of the dissipative coefficient $\Gamma$ for describing the decay of the inflaton field into radiation. By studying the background and perturbative dynamics in the weak and strong dissipative regimes of warm inflation separately for the positive and negative quadratic and quartic potentials, we obtain expressions for the most relevant inflationary observables as the scalar power spectrum, the scalar spectral, and the tensor-to-scalar ratio. We construct the trajectories in the $n_s-r$ plane for several expressions of the dissipative coefficient and compare with the two-dimensional marginalized contours for ($n_s,r$) from the latest Planck data. We find that our results are in agreement with WMAP9 and Planck 2015 data., Comment: 38 pages, 18 figures, accepted for publication in EPJC

The warm inflation scenario in view of the modified Chaplygin gas is studied. We consider the inflationary expansion is driven by a standard scalar field whose decay ratio $\Gamma$ has a generic power law dependence with the scalar field $\phi$ and the temperature of the thermal bath $T$. By assuming an exponential power law dependence in the cosmic time for the scale factor $a(t)$, corresponding to the intermediate inflation model, we solve the background and perturbative dynamics considering that our model evolves according to (i) weak dissipative regime and (ii) strong dissipative regime. Specifically, we find explicit expressions for the dissipative coefficient, scalar potential, and the relevant inflationary observables as the scalar power spectrum, scalar spectral index, and tensor-to-scalar ratio. The free parameters characterizing our model are constrained by considering the essential condition for warm inflation, the conditions for the model evolves according to weak or strong dissipative regime, and the 2015 Planck results through the $n_s-r$ plane., Comment: 30 pages, 6 figures, accepted for publication in EPJC. arXiv admin note: substantial text overlap with arXiv:1704.07005

We investigate the accretion of test fluids onto regular black holes such as Kehagias-Sfetsos black hole and a regular black hole with Dagum Distribution Function. We analyze the accretion process when different test fluids are falling onto these regular black holes. The accreting fluid is being classified through equation of state according to features of regular black holes. The behavior of fluid flow and the existence of sonic points is being checked for these regular black holes. It is noted that three velocity depends on critical points and equation of state parameter on phase space., Comment: 25 pages; 10 Figures