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A possibility to represent the standard model of fundamental particles covariant derivatives by means of approximate generalized fractional Riemann-Liouville derivatives of multifractal time and space model is shown.

High Energy Physics - Theory · Physics 2007-05-23 L. Ya. Kobelev

Durgapal's fifth isotropic solution describing spherically symmetric and static matter distribution is extended to an anisotropic scenario. To do so we employ the gravitational decoupling through the minimal geometric deformation scheme.…

General Relativity and Quantum Cosmology · Physics 2018-11-14 E. Morales , Francisco Tello-Ortiz

Lane-Emden equation could be used to model stellar interiors, star clusters and many configurations in astrophysics. Unfortunately, there is an exact solution only for the polytropic index and . In the present paper, a series solution for…

Solar and Stellar Astrophysics · Physics 2020-03-25 Mohamed I. Nouh , Emad A-B. Abdel-Salam

The Dirac equation plays an essential role in the relativistic quantum systems, which is reduced to a form similar to Schrodinger equation when a certain potential's type is selected as the Cornell potential. By choosing the generalized…

High Energy Physics - Phenomenology · Physics 2023-03-24 M. Abu-Shady , Mohammed K. A. Kaabar

In this paper Einstein's field equations, for static spherically symmetric perfect fluid models with a linear barotropic equation of state, are recast into a 3-dimensional regular system of ordinary differential equations on a compact state…

General Relativity and Quantum Cosmology · Physics 2009-10-31 U. S. Nilsson , C. Uggla

We start by presenting a brief summary of fractional quantum mechanics, as means to convey a motivation towards fractional quantum cosmology. Subsequently, such application is made concrete with the assistance of a case study. Specifically,…

General Relativity and Quantum Cosmology · Physics 2021-05-10 S. M. M. Rasouli , S. Jalalzadeh , P. V. Moniz

We present a general solution of the Einstein gravitational field equations for the static spherically symmetric gravitational interior spacetime of an isotropic fluid sphere. The solution is obtained by transforming the pressure isotropy…

General Relativity and Quantum Cosmology · Physics 2015-06-17 M. K. Mak , T. Harko

In this paper, we first deal with the general fractional derivatives of arbitrary order defined in the Riemann-Liouville sense. In particular, we deduce an explicit form of their null space and prove the second fundamental theorem of…

Classical Analysis and ODEs · Mathematics 2022-02-11 Yuri Luchko

This is a first study of the cosmology of classical fractional gravity, a nonlocal proposal endowed with self-adjoint fractional d'Alembertian operators which serves as the basis for an ultraviolet-complete theory of quantum gravity. We…

General Relativity and Quantum Cosmology · Physics 2026-05-01 Iván Salvador-García , Gianluca Calcagni

The initial state of the spherical gravitational collapse in general relativity has been studied with different methods, especially by using {\it a priori} given equations of state that describe the matter as a perfect fluid. We propose an…

General Relativity and Quantum Cosmology · Physics 2024-10-24 Elly Bayona , Hernando Quevedo , Miguel Alcubierre

We present spectral methods developed in our group to solve three-dimensional partial differential equations. The emphasis is put on equations arising from astrophysical problems in the framework of general relativity.

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Bonazzola , E. Gourgoulhon , J. -A. Marck

A formulation is developed for general relativistic ideal magnetohydrodynamics in stationary axisymmetric spacetimes. We reduce basic equations to a single second-order partial differential equation, the so-called Grad-Shafranov (GS)…

General Relativity and Quantum Cosmology · Physics 2009-10-09 Kunihito Ioka , Misao Sasaki

We present and analyze a space-time Petrov-Galerkin finite element method for a time-fractional diffusion equation involving a Riemann-Liouville fractional derivative of order $\alpha\in(0,1)$ in time and zero initial data. We derive a…

Numerical Analysis · Mathematics 2017-07-26 Beiping Duan , Bangti Jin , Raytcho Lazarov , Joseph Pasciak , Zhi Zhou

A matrix method for the solution of direct fractional Sturm-Liouville problems on bounded domain is proposed where the fractional derivative is defined in the Riesz sense. The scheme is based on the application of the Galerkin spectral…

Numerical Analysis · Mathematics 2017-04-06 Paolo Ghelardoni , Cecilia Magherini

Fractional diffusion equations for three-dimensional lattice models based on fractional-order differences of the Grunwald-Letnikov type are suggested. These lattice fractional diffusion equations contain difference operators that describe…

Statistical Mechanics · Physics 2015-03-13 Vasily E. Tarasov

In this brief review, we present the results of the fractional differential approach in cosmology in the context of the exact models of cosmological accelerated expansion obtained by several authors to date. Most of these studies are…

General Relativity and Quantum Cosmology · Physics 2021-05-18 V. K. Shchigolev

In this work, we derive the general solutions for a cylindrically symmetric space-time filled with a cosmological perfect fluid obeying $p=\gamma \rho$ ($0\leq \gamma \leq 1$), where $\gamma=1$ represents a stiff or Zeldovich fluid. Using…

General Relativity and Quantum Cosmology · Physics 2026-04-06 Tiberiu Harko , Francisco S. N. Lobo , Man Kwong Mak

In this article we investigate mathematically the variant of post-Newtonian mechanics using generalized fractional derivatives. The relativistic-covariant generalization of the classical equations for gravitational field is studied. The…

General Relativity and Quantum Cosmology · Physics 2011-01-21 V. Kobelev

We study the axial gravitational perturbations of slowly-rotating compact objects which are assumed to be supported by anisotropic fluids. We find that the gravitational perturbations decouple from the matter perturbations for axial…

General Relativity and Quantum Cosmology · Physics 2024-12-06 Xing-Hui Feng , Jun Peng

Astrophysical compact objects are usually studied using a perfect fluid model. However, in astrophysical processes out-of-equilibrium, dissipative effects become important to describe the dynamics of the system. In this work, we obtain…

General Relativity and Quantum Cosmology · Physics 2025-08-05 David Díaz-Guerra , Conrado Albertus , Prasanta Char , M. Ángeles Pérez-García