Article
Physics, Particles & Fields
Shi-Bei Kong, Haximjan Abdusattar, Yihao Yin, Hongsheng Zhang, Ya-Peng Hu
Summary: In this paper, we derive the equations of state for the FRW universe in Einstein gravity and a modified gravity. The equation of state from Einstein gravity shows no P-V phase transition, while the equation of state from the modified gravity does, with the critical exponents being the same as those in mean field theory.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Particles & Fields
H. R. Fazlollahi
Summary: The Renyi entropy is a data estimate that incorporates properties of the Shannon entropy and has been widely used in information theory. It has been applied to modify the Friedmann equations and examine the expanding Universe, taking into account quantum effects and the second law of thermodynamics.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Review
Physics, Multidisciplinary
Arieh Ben-Naim
Summary: Time never decreases, but irreversible processes can be reversed with extremely low probability; entropy and the Second Law are timeless.
Article
Physics, Fluids & Plasmas
Juyong Song, Susanne Still, Rafael Diaz Hernandez Rojas, Isaac Perez Castillo, Matteo Marsili
Summary: Szilard's 1929 Gedankenexperiment proposed a theoretical foundation for computing the maximum average work that can be extracted in a multi-particle partition system, which depends on the mutual information of the particle counts in each partition. Below a critical number of particles, symmetric partitioning is optimal, while above this critical number, asymmetric partitioning is favored.
Article
Physics, Multidisciplinary
Lloyd A. Demetrius, Christian Wolf
Summary: The article highlights the concepts of entropy in statistical mechanics and evolutionary dynamics, explaining their manifestations and connections in macroscopic bodies and populations of organisms. It also argues that the Directionality Principle for Evolution is a generalization of the Second Law of Thermodynamics.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Astronomy & Astrophysics
Ujjal Debnath
Summary: In this study, the Friedmann-Robertson-Walker (FRW) Universe is considered as a thermodynamic system with the cosmological constant generating thermodynamic pressure. The study focuses on determining the amount of energy crossing the apparent horizon using a unified first law, and the heat flow through the apparent horizon is found to be equal to the amount of energy crossing. The study also derives equations for various thermodynamic quantities and discusses the cooling/heating nature of the FRW Universe, as well as the heat engine phenomena.
Article
Astronomy & Astrophysics
Masato Minamitsuji
Summary: The analysis shows that the difference between comoving curvature perturbations in the original and new frames on superhorizon scales is determined by a combination of time derivatives, intrinsic entropy perturbations of the scalar field, and their time derivatives. Comoving curvature perturbations can remain invariant under disformal transformations on superhorizon scales under certain conditions, while tensor perturbations can also remain disformally invariant if conserved over time in the original frame.
Article
Engineering, Mechanical
Sangram Kumar Samal, Manoj Kumar Moharana
Summary: This study focuses on the numerical analysis of entropy generation in recharging and simple microchannels, revealing that increasing the number of small channels, channel aspect ratio, and substrate material thermal conductivity can reduce thermal entropy generation, while increasing substrate thickness, channel wall width, and applied heat flux can increase thermal entropy generation.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Physics, Fluids & Plasmas
Ugur Cetiner, Jeremy Gunawardena
Summary: In this study, the properties of steady-state probabilities are investigated. It is found that steady-state probabilities are related to the entropy along minimal paths and can be expressed as averages over a probability distribution on spanning trees. By applying Arrhenius rates to the arboreal distribution, a thermodynamic interpretation for steady-state probabilities is provided. This approach extends equilibrium statistical mechanics and reorganizes the complexity of the expression.
Article
Astronomy & Astrophysics
Gopal Yadav, Nitin Joshi
Summary: In this study, the researchers analyzed the information paradox and its resolution in Schwarzschild de-Sitter black hole spacetime using the island proposal. They found that the black hole island is located inside the black hole event horizon, contrary to the universal result for eternal black holes, and the cosmological island is also located inside the cosmological event horizon. Moreover, they studied the effect of temperature on Page curves and observed that low-temperature black hole/de-Sitter patch exhibits Page curves at later times, while high-temperature black hole/de-Sitter patch shows the opposite behavior.
Article
Mathematics, Interdisciplinary Applications
A. Posadas, J. Morales, J. M. Ibanez, A. Posadas-Garzon
Summary: Earthquakes are non-linear phenomena treated as chaotic natural processes. The use of the Second Law of Thermodynamics and entropy suggests that the relationship between increasing entropy and occurrence of large earthquakes reflects irreversible transitions in a seismic system. Studies in the Canterbury area of New Zealand show theoretical forecasts align with actual results, supporting the idea that earthquakes result in an increase in entropy.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Multidisciplinary Sciences
Gustavo Z. dos Santos Limaid, Joao V. T. de Lima, Joao M. de Araujo, Gilberto Corso, Sergio Luiz E. F. da Silva
Summary: In this study, maximum likelihood estimators associated with generalized Gaussian distributions based on Renyi, Tsallis, and Kaniadakis statistics were proposed. The outlier-resistance of each estimator was analytically analyzed using the influence function. Inverse problems were formulated by constructing objective functions linked to the maximum likelihood estimators. The results showed that the best data inversion performance was achieved when the entropic index from each generalized statistic was associated with objective functions proportional to the inverse of the error amplitude. It was argued that the three approaches were resistant to outliers and equivalent, suggesting a lower computational cost for the inversion process.
Article
Physics, Particles & Fields
Emmanuel N. Saridakis, Spyros Basilakos
Summary: The study found that when the surface of a black hole deforms due to quantum-gravitational effects, the sum of the entropy enclosed by the apparent horizon plus the entropy of the horizon itself is always a non-decreasing function of time, thus validating the generalized second law of thermodynamics. However, if Barrow entropy is applied, the situation may change, and the generalized second law of thermodynamics could be violated depending on the universe's evolution. In order to avoid violation, the deformation from the standard Bekenstein-Hawking expression should be small as expected.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
A. Khodam-Mohammadi, M. Monshizadeh
Summary: This study investigates the modifications to the FLRW cosmology by considering a general entropy for the cosmological apparent horizon. The research explores the impact of correcting the entropy on the energy-momentum tensor of the cosmic fluid by using a correction function. The study demonstrates that the entropic area law can still be considered a general entropy.
Article
Multidisciplinary Sciences
Joe D. Goddard
Summary: This paper revisits the second law of thermodynamics by modifying the axiomatic foundation provided by Caratheodory in 1909. It proposes a new interpretation of thermodynamic entropy and establishes work principles for defining thermodynamic equilibrium and stability based on the convexity properties of internal energy, entropy, and related thermodynamic potentials. The most novel aspect is the extension to irreversible processes through a non-equilibrium entropy derived from recoverable work.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Physics, Nuclear
Farruh Atamurotov, Ibrar Hussain, Ghulam Mustafa, Ali Ovgun
Summary: In this study, the gravitational deflection angle of photons in the weak field limit and shadow cast by the electrically charged and spherically symmetric static Kiselev black hole in the string cloud background are investigated. The influences of the BH charge Q, quintessence parameter gamma, and string cloud parameter a on the weak deflection angle, radius of photon spheres, and size of the BH shadow are studied. Moreover, the effects of plasma on the weak deflection angle and shadow cast by the charged-Kiselev BH surrounded by the clouds of strings are analyzed. Data from the Event Horizon Telescope collaboration are used to obtain constraints on the values of the parameters gamma and a.
Article
Mathematics
Asia Liaqat, Ibrar Hussain
Summary: This paper comprehensively analyzes the approximate Noether and Lie symmetries of the 2nd order for the charged black hole in the Einstein frame. The study shows that there are no new approximate symmetries and no energy rescaling factor observed in this spacetime.
ARABIAN JOURNAL OF MATHEMATICS
(2023)
Article
Physics, Multidisciplinary
G. Mustafa, S. K. Maurya, Ibrar Hussain
Summary: This study investigates wormhole solutions in the f(tau,T) gravity background by utilizing the concept of conformal symmetry. The exact shape functions are calculated using Gaussian and Lorentzian distributions as the noncommutative source of energy density. The presence of exotic matter is confirmed due to the violation of null energy conditions. The physical aspects of epicyclic frequencies and red-blue shifts of test particles in the obtained wormholes are discussed, along with the stability analysis using the Tolman-Oppenheimer-Volkoff equation.
FORTSCHRITTE DER PHYSIK-PROGRESS OF PHYSICS
(2023)
Article
Physics, Mathematical
Gargee Chakraborty, Aroonkumar Beesham, Surajit Chattopadhyay
Summary: Motivated by Nojiri and Odintsov's work, this study reports on the cosmology and baryogenesis of modified f(G) gravity by assuming the background evolution as generalized holographic dark energy (GHDE). The reconstruction of modified f(G) gravity in GHDE shows positive behavior and the corresponding equation of state parameter is phantom-like. There is a possibility of a big rip singularity and the slow roll parameters are analyzed. Quasi-exponential expansion and warm inflation are observed. Finally, baryogenesis is studied, suggesting a symmetry between the number density of baryons and antibaryons in the far future or the satisfaction of the generalized second law of thermodynamics by the model.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2023)
Article
Astronomy & Astrophysics
Gargee Chakraborty, Surajit Chattopadhyay
Summary: Motivated by previous works, this study presents reconstruction schemes for the inhomogeneous equation of state (EoS) and cosmology in the scenario of coupled fluid. Viscosity is considered in an interacting system using the Eckart approach. The EoS parameters for different cosmologies (Little Rip, Pseudo Rip, and Bounce) are rebuilt for both viscous and nonviscous systems, revealing interesting properties such as phantom behavior and violation of energy conditions.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2023)
Article
Physics, Multidisciplinary
Temurbek Mirzaev, Song Li, Bakhtiyor Narzilloev, Ibrar Hussain, Ahmadjon Abdujabbarov, Bobomurat Ahmedov
Summary: We study the effect of strong gravitational field on the light rays emitted from particles in the accretion disk near the Kerr-Newman-NUT-Kiselev (KNNK) black hole in Rastall gravity (RG). The thermal flux of the accretion disk strongly depends on the intensity of the quintessence in the spacetime of the KNNK black hole in RG, and decreases with increasing quintessential intensity. The shadow cast by the KNNK black hole in RG is influenced by the inclination angle of the incident light and the parameters alpha and omega(q) of the quintessence.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Astronomy & Astrophysics
Sanjeeda Sultana, Surajit Chattopadhyay
Summary: This paper presents a detailed study of the generalized Chaplygin gas (GCG) in both interacting and non-interacting scenarios, using different forms of the scale factor. The equation of state (EoS) parameter is analyzed, showing quintessence behavior in the non-interacting case and phantom behavior in the interacting case. The cosmological effects of GCG interacting with pressureless dark matter in the framework of f(T) modified gravity are investigated, and the stability and consistency with observational constraints are examined.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2023)
Article
Physics, Multidisciplinary
G. Mustafa, Ibrar Hussain, Farruh Atamurotov, Wu-Ming Liu
Summary: This study explores the physical effects of dark matter on wormhole geometry in the f (T, T) gravity framework. By analyzing the field equations of f (T, T) gravity using a diagonal tetrad, the study investigates wormhole solutions immersed in galactic halos. The implication of dark matter halos in the framework of f (T, T) gravity leads to novel traversable wormhole solutions that are consistent with the natural prediction of accelerated expansion in the late-time stages of the Universe.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Astronomy & Astrophysics
Sanghati Saha, Surajit Chattopadhyay
Summary: In this study, we investigated bouncing cosmology with modified generalized Chaplygin gas (mgCG) within a bulk viscosity framework. Reconstruction schemes were demonstrated for both Einstein and modified f(T) gravity frameworks, considering both viscous and non-viscous cosmological settings. The equation of state (EoS) parameter and stability of the models were analyzed, indicating that the mgCG behaves like avoidance of Big Rip in the presence of bulk viscosity and exhibits a phantom-like behavior in non-viscous cases. The mgCG's model parameters and the dynamics of the Hubble flow were studied, revealing its capability of realizing an inflationary phase and an exit from inflation. The reconstructed mgCG was found to be stable against small perturbations, regardless of the presence of bulk viscosity and modified gravity scenario. Lastly, the reconstruction scheme was assessed using statistical analysis, Shannon entropy.
Article
Chemistry, Physical
Sanjeeda Sultana, Ertan Gudekli, Surajit Chattopadhyay
Summary: In this paper, we analyzed the properties of generalized Chaplygin gas (GCG) and modified generalized Chaplygin gas (MGCG) in an interacting scenario. We studied the equation of state parameter and stability of the models through squared speed of sound. Our findings showed that both GCG and MGCG, when interacting with pressureless dark matter, exhibit stability against gravitational perturbations. Furthermore, we tested the validity of the generalized second law (GSL) of thermodynamics for different enveloping horizons and found that GSL holds throughout. Additionally, we reconstructed f(T) gravity using GCG and MGCG, and observed phantom behavior through the reconstructed EoS parameters. We derived the squared speed of sound for f(T) gravity and established the stability of the model through its positivity.
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
(2023)
Article
Physics, Multidisciplinary
Rashmi Rekha Devi, Surajit Chattopadhyay
Summary: This study presents a binary fuzzy relation (BFR) based approach to analyze rainfall behavior in northeast India. The results show the relative importance of seasonal rainfall in the annual rainfall, with pre-monsoon rainfall having a moderate influence and a stronger influence when combined with summer monsoon rainfall.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Remote Sensing
Rashmi Rekha Devi, Soumya Banerjee, Surajit Chattopadhyay
Summary: In this study, the total ozone time series in a metropolis in India was examined. The data was obtained through a Brewer spectrophotometer, and the uncertainty of the total ozone time series was thoroughly examined using the Dempster-Shafer method. The association was depicted using three-dimensional graphs, and the prediction capability of the single layer Long Short-Term Memory model was demonstrated using the Adam Optimisation Algorithm and the Rectified Linear Unit.
REMOTE SENSING LETTERS
(2023)
Article
Multidisciplinary Sciences
Sanghati Saha, Ertan Guedekli, Surajit Chattopadhyay
Summary: The study examines the realization of cosmic bounce in two situations with different scale factor selections, one of which is already developed and the other is created by truncating a series expansion. The background fluid in both situations is assumed to be Generalized Chaplygin gas (GCG). The study shows that the GCG energy density decreases during contraction, reaches its lowest point at the bounce, and then increases during expansion. However, the truncation has an impact on the density evolution in the other scale factor scenario.
Article
Geochemistry & Geophysics
Rashmi Rekha Devi, Surajit Chattopadhyay
Summary: Using MF-DFA, this study examined the pre-monsoon rainfall and Indian summer monsoon rainfall in northeast India, and found that both exhibit multifractal behavior.
DYNAMICS OF ATMOSPHERES AND OCEANS
(2023)
Article
Physics, Multidisciplinary
R. R. Devi, P. Bhuiya, S. Chattopadhyay
Summary: This study presents a detailed analysis of rainfall patterns in the Eastern Peninsula region of India using Markov chain analysis. The findings suggest that the overall pattern of annual rainfall is influenced by the Indian summer monsoon rainfall, and the post-monsoon season has minimal impact. Additionally, a rescaled range analysis reveals a long-term switching between high and low values of rainfall, indicating a lack of strong long-term autocorrelation.
INDIAN JOURNAL OF PHYSICS
(2023)
