Article
Physics, Particles & Fields
Pawan Joshi, Sukanta Panda
Summary: A Hamiltonian for the nonlocal F(R) theory is constructed in this work, revealing the nature of the ghost degrees of freedom. Finally, conditions that lead to ghost-free theories are found.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Multidisciplinary
M. Ilyas, Aftab Ahmad, Fawad Khan, M. Wasif
Summary: In this paper, the authors investigate the effects of perfect fluid models and extended f(R, G, T) gravity on the flat Friedmann-Lematre-Robertson-Walker metric. They focus on exploring finite-time future singularities in late-time cosmic accelerating phases using specific f(R, G, T) models. The authors also consider the most recent estimated values for various parameters to examine the viability and bounds of the models induced by different energy conditions.
Article
Astronomy & Astrophysics
V. Sreenivasa Rao, V. Ganesh, K. Dasunaidu
Summary: This study examines an anisotropic cosmological model with massive scalar fields and domain walls in the framework of f(R,T) gravity. The model exhibits a dynamic deceleration parameter and a smooth transition process.
MODERN PHYSICS LETTERS A
(2023)
Article
Astronomy & Astrophysics
Rishi Kumar Tiwari, Aroonkumar Beesham, Bhupendra Kumar Shukla
Summary: Although the standard ΛCDM cosmological model is successful in describing the universe, there are unresolved issues such as the cosmological constant problem and anomalies in the cosmic microwave background radiation. Therefore, examining modified theories to address these problems and exploring all possibilities is interesting. This study focuses on f(R,T) gravity and its homogeneous and isotropic models, which have attractive features like no initial singularity and a transition from early deceleration to late-time acceleration as indicated by observations.
Article
Physics, Mathematical
Iqra Nawazish, Wajiha Javed, Ertan Gudekli, G. Abbas
Summary: This paper examines the cosmic evolution and current expansion of a flat FRW universe through a generalized ghost pilgrim dark energy model in f(R) gravity. The reconstructed models are studied in terms of compatibility, stability, cosmological parameters, and freezing/thawing regions. The results indicate that squared speed of sound identifies stability/instability, while equation of state and deceleration parameters specify the transition from decelerated to accelerated expansion, with the omega-omega planes revealing thawing and freezing regions for certain pilgrim parameter values.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2021)
Article
Physics, Multidisciplinary
M. Zubair, Lala Rukh Durrani
Summary: This paper analyzes Tsallis holographic dark energy in a flat Friedmann-Robertson Walker model under the framework of f(R, T) gravity, studying the effects in a non interactive universe by taking different IR cut-offs. Different cosmological tools are used to study the cosmic evolution, and the impact of various parameters is analyzed. The models exhibit appropriate behavior for the system parameters and support accelerated expansion, showing stability for event horizon partially based on the speed of sound. Various diagnostic mechanisms are used to further examine the behavior of the model, with Om parameter supporting quintessence era and statefinder hierarchy effectively distinguishing the model from the ΛCDM model.
CHINESE JOURNAL OF PHYSICS
(2021)
Article
Physics, Mathematical
Rashid Zia, Dinesh Chandra Maurya, Anil Kumar Shukla
Summary: The paper presents the f(Q,T) gravity theory and investigates a cosmological model based on it, determining the best fit model parameters using observational data and revealing the transition from decelerating to accelerating expansion of the Universe. The calculated signature-flipping point and universe's age are also provided in the study.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2021)
Article
Astronomy & Astrophysics
Takol Tangphati, Sudan Hansraj, Ayan Banerjee, Anirudh Pradhan
Summary: Recent advances in instrumentation and computational methods have led to increased interest in studying the properties of nuclear matter under extreme conditions and the core of neutron stars. By analyzing the observations of pulsars, we investigated compact static configurations composed of interacting quark matter and derived conclusions that provide a more efficient explanation for the observational facts.
PHYSICS OF THE DARK UNIVERSE
(2022)
Article
Astronomy & Astrophysics
Joao R. L. Santos, S. Santos da Costa, Romario S. Santos
Summary: The study explores different cosmological scenarios using the f (R, T) - A(phi) gravity theory, which allows for a description of the accelerated expansion and radiation era of the universe. The results show compatibility with a good description of the radiation era and promising scenarios consistent with current CMB data.
PHYSICS OF THE DARK UNIVERSE
(2023)
Article
Astronomy & Astrophysics
Suresh Kumar, Rafael C. Nunes, Priya Yadav
Summary: We investigate new observational perspectives in f(T) gravity, including the time variation of Newton's constant on the distance modulus relation and the linear perturbations in the framework of f(T) gravity. We find that the constraints obtained from the Pantheon + BAO + BBN analysis are compatible with the ACDM prediction, and the f(T) power-law gravity scenario is practically indistinguishable from the ACDM model when combined with CMB, Pantheon, and BAO data.
Article
Multidisciplinary Sciences
Binaya K. Bishi, Aroonkumar Beesham, K. L. Mahanta
Summary: This manuscript discusses the study of the FLRW universe, domain walls, and quark matter in f(R, T) gravity, obtaining exact solutions under specific assumptions. Physical quantities in cosmological models are graphically analyzed, and the solutions obtained here can reduce to solutions in other gravitational theories with suitable parameter choices.
IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY TRANSACTION A-SCIENCE
(2021)
Article
Multidisciplinary Sciences
A. P. Kale, Y. S. Solanke, S. H. Shekh, A. Pradhan
Summary: This study examines the f(Q, T) theory of gravity, discusses two different forms of the theory, analyzes the physical properties of the models, and obtains the best-fit values using the least squares method.
Article
Physics, Particles & Fields
Julio C. Fabris, Ednaldo L. B. Junior, Manuel E. Rodrigues
Summary: This article investigates the implementation of black bounce solutions in f(R) theories. It is found that violation of the energy conditions still occurs in these solutions, albeit less severe than in General Relativity (GR) cases. The authors propose a zero-density model with horizons and present a model with positive energy density, which differs from GR.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Physics, Nuclear
Juan M. Z. Pretel, Takol Tangphati, Ayan Banerjee, Anirudh Pradhan
Summary: Recent advances in nuclear theory and astrophysical observations have raised the need for specific theoretical models to study dense-matter physics phenomena. This study explores the structure of compact stars composed of a charged perfect fluid in the context of f (R,T) gravity, considering the existence of non-nucleonic degrees of freedom predicted by quantum chromodynamics (QCD).
Article
Physics, Multidisciplinary
Halife Caglar, Dogukan Taser, Sezgin Aygun
Summary: In this article, the Ruban universe is studied in the presence of strange quark matter and normal matter coupled with a domain wall in the f(R,T) alternative gravitation theory. The modified Einstein field equations (MEFE's) are obtained using a classification of f(R,T) as f(R,T) = f (R) thorn 2 mu(T), and the solutions are found with the help of the relationship between metric potentials. The model considers a domain wall matter distribution in the form of a perfect fluid, and strange quark matter and normal matter are connected using equations of states. All solutions are also reduced to General Relativity (GR) by assuming mu = 0, and the article concludes with a discussion of the physical and geometrical perspectives of the f(R,T) and GR theories.
INDIAN JOURNAL OF PHYSICS
(2023)
Article
Astronomy & Astrophysics
B. C. Paul, A. Chanda, A. Beesham, S. D. Maharaj
Summary: This article investigates cosmological models in f(R) modified gravity with coupled Gauss-Bonnet terms. The evolution of the universe is obtained using numerical techniques, and the presence of dark energy and the oscillation properties of parameters are studied. The results show that under certain interaction strengths, the cosmological parameters can exhibit non-singular oscillation characteristics, and the gravitational coupling constant plays an important role. Additionally, in the presence of interactions, energy from the radiation sector cannot flow to other sectors.
CLASSICAL AND QUANTUM GRAVITY
(2022)
Article
Physics, Particles & Fields
Pinki, Pankaj Kumar, Aroonkumar Beesham
Summary: In this paper, the concept of holographic dark energy in the framework of Brans-Dicke theory is reconsidered. The authors investigate the deceleration parameter, Hubble parameter, Brans-Dicke scalar field, and phase transition of the universe. Statefinder diagnostics is applied to compare the model with existing ones.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Chemistry, Physical
Binaya K. Bishi, Aroonkumar Beesham, Kamal L. Mahanta
Summary: In this work, FLRW cosmological models in f(R, T) gravity are developed and the discussion includes the varying deceleration parameter and its consistency with observational data.
ZEITSCHRIFT FUR NATURFORSCHUNG SECTION A-A JOURNAL OF PHYSICAL SCIENCES
(2022)
Article
Astronomy & Astrophysics
B. C. Paul, S. D. Maharaj, A. Beesham
Summary: We present a fiat emergent universe model in modified Gauss-Bonnet gravity in four dimensions, which describes the observed universe well and avoids a big-bang singularity. The model assumes that the present universe emerged from a static Einstein universe phase in the infinite past. By reconstructing mimetic modified f(G)-gravity, the functional form of the model is determined with or without matter, successfully accommodating early inflation and late accelerating phases.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2022)
Article
Astronomy & Astrophysics
Aroonkumar Beesham, Mfanafuthi Siyabonga Msweli
Summary: Dark energy is believed to make up the majority of matter in the universe, and its nature remains poorly understood despite efforts to explain it. This presentation examines the relationship between two potential forms of dark energy, Chaplygin gas and bulk viscosity, and finds that they are mathematically equivalent but differ in their physical interpretation.
INTERNATIONAL JOURNAL OF MODERN PHYSICS D
(2022)
Article
Astronomy & Astrophysics
R. K. Tiwari, D. Sofuoglu, S. K. Mishra, A. Beesham
Summary: In the context of f(R, T) modified gravity theory, two different cosmological models, one decelerating and one accelerating, are considered. The physical and geometric properties of these models, as well as the significance of the modified f(R, T) gravity for these models, are discussed.
GRAVITATION & COSMOLOGY
(2022)
Article
Physics, Nuclear
Aroonkumar Beesham
Summary: In this paper, we explore the emergence of two Rindler space-times caused by the acceleration of black holes around each other, and we find a direct relation between the parameters of the black holes and their observed redshifts.
INTERNATIONAL JOURNAL OF MODERN PHYSICS A
(2022)
Article
Physics, Multidisciplinary
Binaya K. Bishi, P. V. Lepse, A. Beesham
Summary: The Godel universe in f(R, T) gravity is investigated in this paper. The focus is on the first class of the functional form f(R, T) = R + 2h(T), where R is the Ricci scalar and h(T) is an arbitrary function of the trace T of the energy-momentum tensor. Investigations are conducted for three different trace dependent functions h(T) = AT2, h(T) = A ln(T), and h(T) = AeT. The existence of the Godel solution is also demonstrated for the three different trace dependent functions.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
A. Singh, A. Beesham, N. K. Tripathi
Summary: This article considers a flat Friedmann-Robertson-Walker (FRW) universe based on the Hubble parameter. The Hubble parameter ansatz leads to de Sitter-like evolution in the early and late times. The phase transitions from an accelerated to decelerated era in the early times and from a decelerated to an accelerated era in the recent past provide a natural way to understand the complete cosmological history of the universe. By exploring inflationary dynamics, cosmological parameters, energy conditions, and the behavior in the w - w' plane, the article identifies regions of thawing and freezing. The statefinder diagnostic indicates that the universe will evolve into a cold dark matter model in the late times. The article also presents the scalar field description corresponding to the considered Hubble parameter ansatz.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Massimo Fioranelli, Aroonkumar Beesham, Alireza Sepehri
Summary: In this study, a model for building a holographic ultrasound microscope is proposed. By connecting two mobile phones and utilizing the exchange of electromagnetic and sound waves, holographic images of objects can be generated on the phones and a hologram machine. When observing microbes, weak current is sent and amplified, resulting in large holographic images of the microbes on the hologram machine.
ULTRASOUND INTERNATIONAL OPEN
(2022)
Article
Astronomy & Astrophysics
Ashutosh Singh, Anirudh Pradhan, Aroonkumar Beesham
Summary: We investigate the cosmological implications of non-minimal coupling in Brans-Dicke gravity, specifically in the context of LRS BI metric. We derive the field equations and find a relationship between the scale factor and scalar field. This relationship leads to two solutions - an eternally accelerating universe and a transit universe. We also explore the energy transfer between the scalar field and matter sector, showing its dependence on the behavior of the coupling function. Additionally, we analyze the dependence of the effective equation of state parameter and effective energy density on the anisotropy parameter in the transit universe, explaining the late-time accelerating universe evolution.
Article
Biophysics
Massimo Fioranelli, Hijaz Ahmad, Maria Grazia Roccia, Aroonkumar Beesham, Zahir Shah
Summary: This theoretical model proposes the use of entangled graphene sheets to induce T-cells to target tumor cells. The direction of spinors on each sheet affects the other, allowing for communication and deception of tumor cells. The model offers a potential strategy for effectively attacking tumors using the body's own immune cells.
Article
Mathematical & Computational Biology
Massimo Fioranelli, O. Eze Aru, Maria Grazia Roccia, Aroonkumar Beesham, Dana Flavin
Summary: This research proposes a model that predicts the type and characteristics of EEG waves based on parameters such as the exchange of particles within neurons and the movement of particles between neurons.
MATHEMATICAL BIOSCIENCES AND ENGINEERING
(2022)
Article
Biophysics
Massimo Fioranelli, Maria Grazia Roccia, Aroonkumar Beesham, Dana Flavin, M. Ghaeni, Faissal Aziz
Summary: Previous experiments have demonstrated that extremely low frequency electromagnetic fields have significant effects on cell evolution. In this study, a mathematical model was proposed to confirm these findings. The model suggests that electromagnetic waves can induce ion and charge motion, resulting in the generation of currents within and around cells. These currents produce waves that interact with DNA, leading to the attachment or removal of certain repressors. Consequently, gene activation or suppression occurs, enabling cells to acquire or lose specific properties. The experimental results, conducted on quail embryonic cells connected to a battery, revealed the emergence of rings around the cells, possibly indicating their response to changes in electromagnetic waves and electrical currents.
Article
Physics, Multidisciplinary
B. K. Bishi, P. Lepse, A. Beesham
Summary: This manuscript examines the effects of particle creation on cosmological models within the framework of Friedmann-Lemaitre-Robertson-Walker models and Lyra's geometry. The modified field equations and exact solutions for different cosmological models are derived. It is found that the particle creation pressure has an impact on certain cosmological models, and the choice of the deceleration parameter affects the acceptability of the models.
INDIAN JOURNAL OF PHYSICS
(2022)
