Article
Physics, Particles & Fields
Abdulla Al Mamon, Andronikos Paliathanasis, Subhajit Saha
Summary: In this work, the authors extended the analysis on the generalized Chaplygin gas (GCG) model, which unifies dark energy and dark matter. Specifically, they introduced a new generalized Chaplygin gas (NGCG) model that can be described by a scalar field. They studied the perturbations and growth rate in this model and also explored the viability of the generalized second law of thermodynamics by considering the temperature and entropy of the dynamical apparent horizon in a NGCG universe.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Multidisciplinary
N. M. N. da Rocha, G. A. Monerat, F. G. Alvarenga, S. V. B. Goncalves, G. Oliveira-Neto, E. Correa Silva, C. G. M. Santos
Summary: In this study, we analyzed the quantum dynamics and emergence mechanism of the inflationary phase in the Planck era. We numerically quantized a model composed of dust and Chaplygin gas, and calculated the quantum tunneling probabilities. The results showed that models with dust have a higher probability of tunneling compared to models with radiation, indicating that universes with Chaplygin gas and dust are more likely to exist.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Astronomy & Astrophysics
Luis A. Anchordoqui, Ignatios Antoniadis, Dieter Lust
Summary: We investigate the potential connection between 5-dimensional primordial black holes and massive 5-dimensional KK gravitons as candidates for dark matter. Our findings suggest that a population of 5-dimensional black holes with a mass of 7 x 1013 g would be indistinguishable from a KK tower of dark gravitons with a mass of 50 keV in the local universe. Furthermore, we establish a link between the increase in mass of 5-dimensional black holes and the decrease in temperature with the cooling of the tower of massive spin-2 KK excitations of the graviton.
Article
Physics, Particles & Fields
Rattanasak Hama, Tiberiu Harko, Sorin Sabau
Summary: Finsler geometry is an important extension of Riemann geometry with various physical applications. The osculating Finsler spaces, a subclass of Finsler geometries, are characterized by having the internal variable as a function of the base manifold coordinates only. This work investigates the gravitational and cosmological implications of a Barthel-Kropina type geometry, and finds that it admits de Sitter type solutions and can generate effective dark energy components.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Multidisciplinary Sciences
Cosmin Andrei, Anna Ijjas, Paul J. Steinhardt
Summary: In this paper, we investigate how short the remaining period of expansion can be given current observational constraints on dark energy, and discuss how this scenario fits naturally with cyclic cosmologies and recent conjectures about quantum gravity.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Astronomy & Astrophysics
Priyanka Adhikary, Sudipta Das, Spyros Basilakos, Emmanuel N. Saridakis
Summary: The study discusses the construction of Barrow holographic dark energy in nonflat universe, deriving differential equations for the evolution of dark-energy density parameter and providing analytical expression for the dark energy equation-of-state parameter. The scenario is shown to describe the thermal history of the universe and the sequence of matter and dark energy epochs. Comparisons with flat cases and different spatial geometries reveal interesting behaviors in the evolution of dark-energy equation-of-state parameters under Barrow exponent variations. Incorporating slightly non-flat spatial geometry improves the phenomenology of Barrow holographic dark energy while maintaining smaller values for the new Barrow exponent.
Article
Physics, Multidisciplinary
Narges Badri, Farhad Zamani
Summary: This study examines a new model called Emergent Cosmology that aims to address the problem of the big-bang singularity in standard cosmology and inflation theory. By analyzing different cosmological scenarios and utilizing two methods, the researchers find that it is possible to have a stable Emergent Universe in a flat, open, or closed Friedmann-Robertson-Walker background.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Astronomy & Astrophysics
Fei Huang, Veronica Sanz, Jing Shu, Xiao Xue
Summary: The article demonstrates how current LIGO data can probe interesting theories beyond the Standard Model, particularly dark sectors where a dark Higgs boson triggers symmetry breaking via a first-order phase transition. It shows that the LIGO measurements are testing a broad set of scenarios in the dark sector models with reasonable parameters for the scalar potential.
Article
Astronomy & Astrophysics
Xiang-Qian Li, Hao-Peng Yan, Li-Li Xing, Shi-Wei Zhou
Summary: A static spherically symmetric black hole solution is obtained for the Einstein gravitational equations in the presence of a Chaplygin-like dark fluid. The black hole exhibits a small/large phase transition similar to the van der Waals system in the extended phase space. Additionally, the low-/high-phi phase transition of the black hole in the nonextended phase space is studied, and the critical exponents and scaling behavior of thermodynamic quantities near criticality are derived. The "shadow thermodynamics" of AdS black holes surrounded by the Chaplygin-like dark fluid is also investigated, revealing a positive correlation between the shadow radius and the event horizon radius.
Article
Astronomy & Astrophysics
Rodrigo von Marttens, Dinorah Barbosa, Jailson Alcaniz
Summary: Einstein's equations connect the space-time geometry to the total matter content of the cosmic substratum, but not to individual contributions of the matter species. Therefore, it is difficult to differentiate cases where dark energy interacts with dark matter from a non-interacting scenario using observational data based on time or distance measurements.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
David McKeen, Marianne Moore, David E. Morrissey, Maxim Pospelov, Harikrishnan Ramani
Summary: In this study, we propose two new methods of detecting strongly interacting dark matter by scattering the enhanced population near the Earth. These methods involve using underground nuclear accelerator beams or intense thermal sources to accelerate dark matter and detect it with dark matter detectors.
Article
Astronomy & Astrophysics
Gaurav N. Gadbail, Simran Arora, P. K. Sahoo
Summary: The generalized Chaplygin gas (GCG) coupled with baryonic matter in a proposed f(Q, T) gravity is investigated. Two different functional forms of the f(Q, T) model under high pressure and high-density scenarios of GCG are obtained. The models are tested with observational data sets and the transition from decelerated to accelerated universe expansion as well as the behavior of the equation of state parameter during acceleration are predicted. The statefinder diagnostic is used to distinguish between the GCG and other dark energy models.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Astronomy & Astrophysics
Xiao-Min Zhang, Kai Li, Yi-Fu Guo, Peng-Cheng Chu, He Liu, Jian-Yang Zhu
Summary: Two models proposed in this study unify warm inflation with dark matter and dark energy. A single scalar field is responsible for early Universe expansion through dissipative warm inflation and later acts as both dark matter and dark energy. Evolution equations for the fields and observational constraints are presented, along with an evolution law describing the scaling of energy density and state parameter with scale factor.
Article
Astronomy & Astrophysics
Philip Bull, Martin White, Anze Slosar
Summary: This study investigates constraints on the behavior of dynamical dark energy in the matter-dominated era, finding that existing CMB and LSS measurements have constrained the dark energy equation of state during this period. It also examines how forthcoming galaxy surveys and 21cm intensity mapping instruments can further improve constraints in this regime.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Farbod Hassani, Julian Adamek, Martin Kunz
Summary: Studying cosmological observables on the past light-cone of a fixed observer in the context of clustering dark energy reveals that the integrated Sachs-Wolfe and non-linear Rees-Sciama effect is the most promising probe for constraining clustering dark energy properties, with weak gravitational lensing, Shapiro time delay, and gravitational redshift showing less sensitivity and small variations. The negligible impact of dark energy non-linearities at low l becomes more significant at higher multipoles, reaching about 2% and 3% in the convergence and ISW-RS angular power spectra.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Physics, Nuclear
Sen Yang, Cheng Liu, Tao Zhu, Li Zhao, Qiang Wu, Ke Yang, Mubasher Jamil
Summary: This study investigates the spherical accretion flow onto general parametrized spherically symmetric black hole spacetimes, analyzing the accretion process for various perfect fluids. The influences of additional parameters beyond the Schwarzschild black hole on flow behavior are studied in detail, as well as the accretion of the ideal photon gas and its correspondence with the photon sphere for general parameterized spherically symmetric black holes. Possible extensions of the analysis are also discussed.
Correction
Physics, Particles & Fields
Sanjar Shaymatov, Bobomurat Ahmedov, Mubasher Jamil
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
Sanjar Shaymatov, Bobomurat Ahmedov, Mubasher Jamil
Summary: This study tests the weak cosmic censorship conjecture for the Reissner-Nordstrom-de Sitter black hole surrounded by perfect fluid dark matter, showing that even in a realistic scenario with cosmological parameters, the black hole cannot be overcharged unless the induced fields by dark matter and cosmological parameters are completely balanced. Additionally, it is found that a certain threshold limit exists beyond which the black hole cannot be overcharged, indicating that the effect of the cosmological constant dominates over the effect of perfect fluid dark matter in the overcharging process.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Particles & Fields
Seyed Hossein Hendi, Somayeh Hajkhalili, Mubasher Jamil, Mehrab Momennia
Summary: This paper investigates the thermodynamics and phase transitions of a four-dimensional rotating Kaluza-Klein black hole solution in the presence of Maxwell electrodynamics. The stability of the black hole is checked in the canonical ensemble by analyzing the behavior of the heat capacity. Additionally, the study explores massive scalar perturbations coupled to the background geometry of the static Kaluza-Klein black hole and investigates quasinormal modes using the WKB approximation.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Mathematical
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Tao Zhu
Summary: This paper investigates the effects of the Generalized Uncertainty Principle (GUP) on the shadow and quasinormal modes (QNMs) of GUP-modified Kerr black holes. The study reveals that the GUP modification increases the curvature radius of the shadow and that it increases linearly with the GUP parameter. By using observational data and fitting techniques, the upper limits of the GUP parameter and the correction parameter in the modified black hole metric are determined.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Emmanuel N. Saridakis
Summary: Using observations of the central black hole and stars, we extract constraints on Barrow entropy, finding an upper bound less strong than the Big Bang Nucleosynthesis but significantly stronger than late-time cosmological constraints.
Article
Astronomy & Astrophysics
Javlon Rayimbaev, Bushra Majeed, Mubasher Jamil, Kimet Jusufi, Anzhong Wang
Summary: In this article, we investigate the particle dynamics around a Bardeen-Kiselev black hole, including its geometrical properties, the dynamics of test particles, and the relationship with rotating Kerr black hole.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Astronomy & Astrophysics
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Qiang Wu
Summary: This paper focuses on the relationship between quasinormal modes (QNMs) and a rotating black hole shadow, using the example of a quantum deformed Kerr black hole. The study shows that, in the eikonal limit, the real part of QNMs is related to the Keplerian frequency for equatorial orbits. The paper also explores the typical shadow radius, computes the corresponding modes, and investigates the thermodynamical stability of the quantum deformed Kerr black hole, as well as other astrophysical applications.
Article
Astronomy & Astrophysics
Javlon Rayimbaev, Ahmadjon Abdujabbarov, Mubasher Jamil, Wen-Biao Han, Malika Khudoyberdieva
Summary: This paper discusses the motion of various types of charged, magnetized, and neutral test particles near static and spherically symmetric electrically charged black holes in the Einstein-/Ether gravitational theory. The effects of the free parameters in the theory on particle motion in curved spacetime are analyzed, focusing on the stability of circular and radially varying orbits for different types of particles. The behavior of charged particle motion around black holes with a uniform magnetic field is investigated, and values of the parameters c13 and c14 are proposed to model astrophysical black holes based on the spin of Kerr black holes.
MODERN PHYSICS LETTERS A
(2022)
Article
Physics, Nuclear
Farruh Atamurotov, Mubasher Jamil, Kimet Jusufi
Summary: In this study, the optical properties of a renormalization group improved Schwarzschild black hole in a plasma medium are investigated. The deflection angle of light in the weak gravity regime is computed for uniform and non-uniform plasma media, revealing the modifications caused by the plasma medium. The effects of plasma media play an important role in the optical appearance of black holes.
Article
Physics, Particles & Fields
Kimet Jusufi, Salvatore Capozziello, Sebastian Bahamonde, Mubasher Jamil
Summary: We use observational data to constrain a black hole solution of extended teleparallel gravity models based on the S2 star orbiting the Galactic Center. We construct the shadow images of the Sgr A* black hole and find that the shadow radius increases with the parameter alpha. The observables, such as the deflection angle and angular diameter, are close to the Schwarzschild case. However, the electromagnetic intensity observed in the shadow images is smaller compared to General Relativity (GR), indicating differences in the Born-Infeld f(T) gravity.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
Kimet Jusufi, Saurabh Kumar, Mustapha Azreg-Ainou, Mubasher Jamil, Qiang Wu, Cosimo Bambi
Summary: In this study, we investigate the possibility of a wormhole as a candidate for the central object of Sgr A(star) and test this idea by constraining their geometry using the motion of S2 star and the reconstructed shadow images. We consider three wormhole models and find that they satisfy the flare out condition. We also explore the accretion of infalling gas model and study the accretion rate, electromagnetic radiation intensity, and shadow images.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
Sanjar Shaymatov, Mubasher Jamil, Kimet Jusufi, Kazuharu Bamba
Summary: In this study, we investigate the dynamics of test particles around a magnetized Ernst black hole, taking into account its surrounding magnetic field. We find that the magnetic field has a significant impact on the radius of the innermost stable circular orbit (ISCO) and the epicyclic frequencies, especially for charged particles. By analyzing the astrophysical quasiperiodic oscillation (QPO) data of three microquasars, we determine the order of magnitude of the magnetic field.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Correction
Astronomy & Astrophysics
Cheng Liu, Tao Zhu, Qiang Wu, Kimet Jusufi, Mubasher Jamil, Mustapha Azreg-Ainou, Anzhong Wang
Article
Astronomy & Astrophysics
Kimet Jusufi, Mustapha Azreg-Ainou, Mubasher Jamil, Shao-Wen Wei, Qiang Wu, Anzhong Wang
Summary: This paper obtains an effective metric describing a regular and rotating magnetic black hole solution and studies various properties including BH shadow, QNMs, QPOs, and observational constraints on the EYM parameter. The study shows interesting correlations between the magnetic charge, shadow radius, and QNMs of scalar and electromagnetic fields, also distinguishing the rotating EYM black hole from the Kerr-Newman black hole.
