Searcharxiv⌕ Search

arXiv subjects

Fatemah Mofarreh

Publications and source records attributed to Fatemah Mofarreh.

6 recordsLinked to original sources
arXiv2026

Charged Anisotropic Compact Stars in $f(R,ϕ,X)$ Gravity: A Class I Embedding Approach with Reissner-Nordström Exterior

This work examines the physical characteristics of charged, anisotropic compact spheres within the framework of $f(R,ϕ,X)$ modified gravity. Starting from a static, spherically symmetric spacetime, we employ an Adler-type ansatz for the temporal metric component $g_{tt}$. The corresponding radial metric component $g_{rr}$ is then systematically derived through application of the Karmarkar condition, which ensures a class-one embedding for the interior geometry. A crucial aspect of our approach involves matching the interior solution at the stellar boundary to the exterior Reissner--Nordstr$\ddot{0}$m spacetime---the established vacuum solution for charged, non-rotating masses. This matching procedure is essential for determining integration constants and verifying global physical consistency. Our comprehensive analysis of the resulting stellar model investigates multiple physical aspects, including energy density, radial and tangential pressures, anisotropy, equation-of-state parameters, energy conditions, mass function, compactness, and surface redshift. Stability assessment further incorporates examination of the adiabatic index and the Tolman--Oppenheimer--Volkoff equation. Collectively, our findings demonstrate that the charged compact star model presented here constitutes a physically viable configuration---free of singularities and maintaining stable equilibrium across the considered parameter space.

physics.gen-ph↗
arXiv2026

Cosmological bouncing solutions and their stability in teleparallel gravity

The cosmological dynamics in the early universe are investigated to explore the possibility of the sign reversal of the Hubble parameter as a key feature of non-singular bouncing cosmological solutions in higher-order torsion gravity. The self-consistent multiple cosmological regimes are studied, such as the accelerated expansion, ultra-relativistic, radiation-dominated, sub-relativistic, dust, and stiff matter phases, for three distinct parametrizations of the scale factor: power-law, exponential, and hybrid forms. In particular, five characteristic bouncing scenarios are analyzed: symmetric bounce, super-bounce, oscillatory bounce, matter bounce, and Type IV singularity-free bounce, so that the gravitational Lagrangian can be reconstructed to satisfy bounce conditions at the bounce time. It is found that each scenario requires a violation of the null energy condition, implying the presence of exotic matter with an effective equation of state to drive both the bounce and late-time cosmic acceleration. As a result, it is explicitly demonstrated that higher-order torsion gravity naturally incorporates the bouncing solutions without introducing ad hoc matter fields, providing a possible geometric framework for non-singular early universe evolution. Furthermore, the consistency of the bouncing solutions with the observational constraints of the cosmic microwave background and gravitational wave spectrum is shown, while offering testable predictions for primordial perturbations.

gr-qc↗
arXiv2023

Geometry of statistical submanifolds of statistical warped product manifolds by optimization techniques

This paper deals with the applications of an optimization method on submanifolds, that is, geometric inequalities can be considered as optimization problems. In this regard, we obtain optimal Casorati inequalities and Chen-Ricci inequality for a statistical submanifold in a statistical warped product manifold of type $\mathbb{R} \times_{\mathfrak{f}} \overline{M}$ (almost Kenmotsu statistical manifold), where $\mathbb{R}$ and $\overline{M}$ are trivial statistical manifold and almost Kaehler statistical manifold, respectively.

math.DG↗
arXiv2021

Interpolation of surfaces with asymptotic curves in Euclidean 3-space

In this paper, we investigate the interpolation of surfaces which are obtained from an isoasymptotic curve in 3D-Euclidean space. We prove that there exist a unique $ C^0 $-Hermite surface interpolation related to an isoasymptotic curve under some special conditions on the marching scale functions. Finally, we present some examples and plot their graphs.

math.GM↗
arXiv2021

Geometry of almost contact metrics as almost $*$-Ricci solitons

In the present paper, we give some characterizations by considering $*$-Ricci soliton as a Kenmotsu metric. We prove that if a Kenmotsu manifold represents an almost $*$-Ricci soliton with the potential vector field $V$ is a Jacobi along the Reeb vector field, then it is a steady $*$-Ricci soliton. Next, we show that a Kenmotsu matric endowed an almost $*$-Ricci soliton is Einstein metric if it is $η$-Einstein or the potential vector field $V$ is collinear to the Reeb vector field or $V$ is an infinitesimal contact transformation.

math.DG↗