Showing papers in "International Journal of Geometric Methods in Modern Physics in 2021"
TL;DR: A short review on the status of research on the theoretical foundations of gravity theories can be found in this article, where the authors discuss recent results on perturbative and non-perturbative approaches, causality and deformation.
Abstract: We give a short review on the status of research on the theoretical foundations of f(𝕋) gravity theories. We discuss recent results on perturbative and non-perturbative approaches, causality and de...
38 citations
TL;DR: For the spherical unit speed nonlightlike curve in pseudo-hyperbolic space and de Sitter space γ and a given point P, the pedal curve of γ relative to the pedal point P was defined in this paper.
Abstract: For the spherical unit speed nonlightlike curve in pseudo-hyperbolic space and de Sitter space γ and a given point P, we can define naturally the pedal curve of γ relative to the pedal point P. Whe...
31 citations
TL;DR: F(Q,T) gravity as mentioned in this paper is an extension of the symmetric teleparallel gravity, in which the gravitational action is given by an observer, and it is a recently proposed modified theory of gravity due to Xu et al.
Abstract: f(Q,T) gravity is a recently proposed modified theory of gravity due to Xu et al. (2019). It is an extension of the symmetric teleparallel gravity, in which the gravitational action is given by an ...
23 citations
TL;DR: In this article, the authors considered Barrow holographic dark energy (BHDE) proposed in E. N. Saridakis and E. E. Barrow as a special case of m...
Abstract: In the work reported here we have considered Barrow holographic dark energy (BHDE) proposed in E. N. Saridakis, Barrow holographic dark energy, Phys. Rev. D 102 (2020) 123525 as a special case of m...
22 citations
TL;DR: In this article, Tsallis holographic quintessence model of dark energy in f(R,T) gravity with Hubble horizon as infrared (IR) cut-off was constructed.
Abstract: In the present work, we construct the Tsallis holographic quintessence model of dark energy in f(R,T) gravity with Hubble horizon as infrared (IR) cut-off. In a flat Friedmann–Robertson–Walker (FRW...
20 citations
TL;DR: In this paper, the dark energy behavior of the viscus-fluid in f(Q)-gravity in a flat, isotropic and homogeneous Friedmann-Lemaitre-Robertson-Walker (FLRW) space-time metric was investigated.
Abstract: In this study, we have investigated the dark energy behavior of the viscus-fluid in f(Q)-gravity in a flat, isotropic and homogeneous Friedmann–Lemaitre–Robertson–Walker (FLRW) space-time metric. W...
19 citations
TL;DR: In this paper, the notion of cosmological symmetry, i.e., spatial homogeneity and isotropy, is considered in the field of teleparallel gravity and geometry.
Abstract: We consider the notion of cosmological symmetry, ie spatial homogeneity and isotropy, in the field of teleparallel gravity and geometry, and provide a complete classification of all homogeneous a
19 citations
TL;DR: In this article, the modified study of f(Q,T) is elucidated as Cosmological model, in which the action holds a role as a capriciou...
Abstract: Xu et al. (Eur. Phys. J. C 79 (2019) 708) have anticipated the theory of Gravity. The modified study of f(Q,T) is elucidated here as Cosmological model. In it the action holds a role as a capriciou...
18 citations
TL;DR: In this paper, the authors derived the energy density of dark fluid and dark matter component for both the cases of inhomogeneous EOS of the form pd = w(t)ρd + w1f(H,t)
Abstract: In this paper, we study two different cases of inhomogeneous EOS of the form pd = w(t)ρd + w1f(H,t) We derive the energy density of dark fluid and dark matter component for both the cases Further
17 citations
TL;DR: In this paper, a few questions related to white dwarfs' physics are posed and it seems that the modified gravity framework can be a good starting point to provide alternative explanations to cooling processes, their...
Abstract: A few questions related to white dwarfs’ physics is posed. It seems that the modified gravity framework can be a good starting point to provide alternative explanations to cooling processes, their ...
17 citations
TL;DR: In this article, the usual Einstein-Hilbert action in a metric-affine setup and in the presence of a perfect hyperfluid was considered and the role of shear hypermomentum was decoded.
Abstract: We consider the usual Einstein–Hilbert action in a Metric-Affine setup and in the presence of a Perfect Hyperfluid. In order to decode the role of shear hypermomentum, we impose vanishing spin and ...
TL;DR: In this paper, the authors introduced and established group invariant results of (2 + 1)-dimensional mKdV-Calogero-Bogoyavlenskii-Schiff equation.
Abstract: In this paper, we introduced and established some group invariant results of (2 + 1)-dimensional mKdV–Calogero–Bogoyavlenskii–Schiff equation. Using the one-parameter Lie-group of transformations, ...
TL;DR: In this paper, a modified teleparallel theory of gravity is described in terms of the tetrad of a metric and a flat connection with torsion, and spherical symmetry is studied.
Abstract: Teleparallel theories of gravity are described in terms of the tetrad of a metric and a flat connection with torsion. In this paper, we study spherical symmetry in a modified teleparallel theory of...
TL;DR: In this article, the equivalence classes for electromagnetic potentials and space-time metrics of Stackel spaces were defined for the Hamilton-Jacobi equation and Klein-Gordon-Fock equation for a charged test particle.
Abstract: All equivalence classes for electromagnetic potentials and space-time metrics of Stackel spaces provided that Hamilton–Jacobi equation and Klein–Gordon–Fock equation for a charged test particle can...
TL;DR: In this article, the authors investigated dust acoustic solitary waves in dusty inhomogeneous plasma with a weak density gradient and used Lie analysis to obtain the acoustic solitary wave in the presence of dust.
Abstract: In this paper, we investigate dust acoustic solitary waves in dusty inhomogeneous plasma with a weak density gradient. For this, Lie analysis is utilized and solitary waves are obtained with the ai...
TL;DR: In this article, a non-interacting model of Barrow holographic dark energy (BHDE) using Barrow entropy in a spatially flat FLRW universe considering the IR cutoff as the Hubble horizon was proposed.
Abstract: In this work, we propose a non-interacting model of Barrow holographic dark energy (BHDE) using Barrow entropy in a spatially flat FLRW Universe considering the IR cutoff as the Hubble horizon. We ...
TL;DR: In this paper, it was shown that for a kenmotsu manifold M which admits an η-Ricci-Yamabe soliton, then the soliton can be replaced by a soliton of the following form:
Abstract: The objective of this paper is to deal with Kenmotsu manifolds admitting η-Ricci-Yamabe solitons. First, it is proved that if a Kenmotsu manifold M which admits an η-Ricci-Yamabe soliton, then the ...
TL;DR: In this paper, the analytical solutions of the Klein-Gordon equation for any l states of the modified effective mass potential under the modified unequal scalar and vector Coulomb-Hulthen potential were presented.
Abstract: In this study, the analytical solutions of the Klein–Gordon equation for any l states of the modified effective mass potential under the modified unequal scalar and vector Coulomb–Hulthen potential...
TL;DR: In this paper, a special algorithm for the feed-forward neural network method (FNNM) was proposed to compute the quasinormal modes (QNMs) complying with certain types of boundary conditions.
Abstract: In this paper, we show how the quasinormal modes (QNMs) arise from the perturbations of massive scalar fields propagating in the curved background by using the artificial neural networks. To this end, we architect a special algorithm for the feedforward neural network method (FNNM) to compute the QNMs complying with the certain types of boundary conditions. To test the reliability of the method, we consider two black hole spacetimes whose QNMs are well-known: $4D$ pure de Sitter (dS) and five-dimensional Schwarzschild anti-de Sitter (AdS) black holes. Using the FNNM, the QNMs of are computed numerically. It is shown that the obtained QNMs via the FNNM are in good agreement with their former QNM results resulting from the other methods. Therefore, our method of finding the QNMs can be used for other curved spacetimes that obey the same boundary conditions.
TL;DR: In this paper, the authors compare different approaches to the Hamiltonian analysis of teleparallel theories of gravity and present the primary constraints of the $f({\mathbb{T}_{\textrm{NGR})$ gravity class of theories.
Abstract: We review different approaches to the Hamiltonian analysis of teleparallel theories of gravity. In particular the Hamiltonian analysis for $f(\mathbb{T})$ theories led to disputed results in the literature. The aim of this review is to relate the different notations and assumptions in the different approaches in a comprehensive way, so that they can be compared more easily. To do this we present the primary constraints of the $f({\mathbb{T}_{\textrm{NGR}}})$ gravity class of theories for the first time. The particular cases studied in the literature, $f(\mathbb{T})$ gravity and new general relativity, are contained in this parent theory. We compare their Hamiltonian analyses done by different authors in the literature among each other by relating them to our analysis of $f({\mathbb{T}_{\textrm{NGR}}})$ in detail.
TL;DR: In this paper, the existence of equilibrium points for a particle or dust grain in the framework of unperturbed and perturbed Robe's motion is analyzed in a spherical nebula.
Abstract: We analyze the existence of equilibrium points for a particle or dust grain in the framework of unperturbed and perturbed Robe’s motion. This particle is moving in a spherical nebula consisting of ...
TL;DR: In this article, the authors investigated the gravitational lensing by asymptotically flat black holes in the framework of Horndeski theory in weak field limits, where the curvature of the weak field is constant.
Abstract: The principal objective of this project is to investigate the gravitational lensing by asymptotically flat black holes in the framework of Horndeski theory in weak field limits. To achieve this obj...
TL;DR: In this paper, the interior geometry of static relativistic charged spheres in the background of a modified f(G,T) gravity was explored, where G and T are the Gauss-Bonnet invariant invariants.
Abstract: This study explores the interior geometry of static relativistic charged spheres in the background of a recently proposed modified f(G,T) gravity, where G and T are the Gauss–Bonnet (GB) invariant ...
TL;DR: In this paper, the Noether Symmetry Approach is applied to point-like teleparallel Lagrangians in view to derive minisuperspaces suitable for Quantum Cosmology.
Abstract: We apply the Noether Symmetry Approach to point-like teleparallel Lagrangians in view to derive minisuperspaces suitable for Quantum Cosmology. Adopting the Arnowitt–Deser–Misner formalism, we find...
TL;DR: In this paper, a pseudo-null space curve in Minkowski 3-space is used to describe an optical fiber that is injected into monochromatic linear polarized light.
Abstract: In this study, a pseudo-null space curve in Minkowski 3-space is used to describe an optical fiber that is injected into monochromatic linear polarized light. The direction of the electric field ve...
TL;DR: In this paper, a new frame and new transformation associated with combined Korteweg-de Vries-modified KdV-mKdV equation with respect to the kdV equations was introduced.
Abstract: In this paper, we introduce new frame and new transformation associated with combined Korteweg–de Vries–modified Korteweg–de Vries (KdV–mKdV) equation, the mKdV and the KdV equations with respect t...
TL;DR: In this paper, a new approach of spherical magnetic Lorentz flux of spherical 𝕊α-magnetic flows of particles by the spherical frame in spherical space is presented.
Abstract: In this paper, we construct a new approach of spherical magnetic Lorentz flux of spherical 𝕊α-magnetic flows of particles by the spherical frame in 𝕊2 spherical space. Eventually, we obtain some op...
TL;DR: In this paper, the shadow behaviors of four-dimensional charged rotating black holes with a cosmological constant were investigated in terms of a r-approximation of the Gaussian distribution.
Abstract: Motivated by recent astrophysical observations, we investigate the shadow behaviors of four-dimensional charged rotating black holes with a cosmological constant. This study is made in terms of a r...
TL;DR: In this paper, the existence of compact star model in the context of modified gravity with Ricci scalar and trace of energy-momentum tensor is discussed and the corresponding field equations are solved by choosing well known Finch-Skea equation.
Abstract: The present work discusses about the existence of compact star model in the context of $f(R,T)$ gravity with $R$ as the Ricci scalar and $T$ as the trace of energy-momentum tensor $T_{\mu
u}$. The model has been developed by considering the spherically symmetric spacetime consisting of isotropic fluid with $f(R,T)=R+2 \beta T$ with $\beta$ be the coupling parameter. The corresponding field equations are solved by choosing well known Finch-Skea {\em ansatz} [Finch, M.R., Skea, J.E.F.:{\it Class. Quantum Gravity}{\bf 6}, 467 (1989)]. For spacetime continuity we elaborate the boundary conditions by considering the exterior region as Schwarzschild metric. The unknown constants appearing in the solution are evaluated for the compact star PSR~J 1614-2230 for different values of coupling constant. The physical properties of the model, e.g., matter density, pressure, stability etc. have been discussed both analytically and graphically. This analysis showed that the geometry and matter are compatible with each other as well as the model is in stable equilibrium in the context of $f(R,\,T)$ modified gravity.
TL;DR: In this paper, the existence and uniqueness of Levi-Civita connections for strongly σ-compatible pseudo-Riemannian metrics on tame differential calculi was proved.
Abstract: We prove the existence and uniqueness of Levi-Civita connections for strongly σ-compatible pseudo-Riemannian metrics on tame differential calculi. Such pseudo-Riemannian metrics properly contain th...