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Related papers: Conformable Fractional Isothermal Gas Spheres

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We consider a thermodynamically consistent approach for the computation of the masses, radii, and tidal deformabilities of compact stars consisting of two interacting fluids with separately conserved quantum numbers. We apply this…

High Energy Physics - Phenomenology · Physics 2026-02-25 Fazlollah Hajkarim , Jürgen Schaffner-Bielich , Laura Tolos

Recently, a new fractional derivative called the conformable fractional derivative is given which is based on the basic limit definition of the derivative in [1]. Then, the fractional versions of chain rules, exponential functions,…

Classical Analysis and ODEs · Mathematics 2016-02-19 Emrahünal , Ahmet Gökdoğan

In the present paper we analyze and discuss some mathematical aspects of the fluid-static configurations of a self-gravitating perfect gas enclosed in a spherical solid shell. The mathematical model we consider is based on the well-known…

Spatially homogeneous thermal equilibria of self-gravitating gas, being impossible otherwise, are nevertheless allowed in an expanding background accounting for Universe's expansion. Furthermore, a fixed density at the boundary of a…

Astrophysics of Galaxies · Physics 2024-12-13 Zacharias Roupas

We study the consistency and convergence of smoothed particle hydrodynamics (SPH), as a function of the interpolation parameters, namely the number of particles $N$, the number of neighbors $n$, and the smoothing length $h$, using…

Instrumentation and Methods for Astrophysics · Physics 2017-02-08 Ruslan Gabbasov , Leonardo Di G. Sigalotti , Fidel Cruz , J. Klapp , J. M. Ramírez-Velasquez

A numerical procedure was developed for solving equations for compressible granular multiphase flows in which the particle volume fraction can range dynamically from very dilute to very dense. The procedure uses a low-dissipation and…

Computational Physics · Physics 2014-10-20 Ryan W. Houim , Elaine S. Oran

We present an analytic formulation for the equilibrium gas density profile of early-type galaxies that explicitly includes the contribution of stars in the gravitational potential. We build a realistic model for an isolated elliptical…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-10 Pedro R. Capelo , Priyamvada Natarajan , Paolo S. Coppi

We investigate exact solutions for isothermal shock problems in different one-dimensional geometries. These solutions are given as analytical expressions if possible, or are computed using standard numerical methods for solving ordinary…

Fluid Dynamics · Physics 2018-02-20 Stephan C. Deschner , Tobias F. Illenseer , Wolfgang J. Duschl

A numerical solution of Einstein field equations for a spherical symmetric and stationary system of identical and auto-gravitating particles in phase transition is presented. The fluid possess a perfect fluid energy momentum tensor, and the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Jose D. Polanco , Patricio S. Letelier , Maximiliano Ujevic

A numerical method to solve the fractional diffusion equation, which could also be easily extended to many other fractional dynamics equations, is considered. These fractional equations have been proposed in order to describe anomalous…

Numerical Analysis · Mathematics 2025-10-20 S. B. Yuste , L. Acedo

A new class of solutions describing analytical solutions for compact stellar structures has been developed within the tenets of General Relativity. Considering the inherent anisotropy in compact stars, a stable and causal model for…

General Relativity and Quantum Cosmology · Physics 2021-10-14 Jay Solanki , Bhashin Thakore

Stellar cores may be considered as a nuclear reactor that play important role in injecting new synthesized elements in the interstellar medium Helium burning is an important stage that contribute to the synthesis of key elements such as…

Solar and Stellar Astrophysics · Physics 2020-03-25 Mohamed I. Nouh

We take up the investigation we left in the future-work stack in Giordano \textit{et al.} [``Fluid statics of a self-gravitational isothermal sphere of van der Waals' gas,'' Phys. Fluids \textbf{36}, 056127 (2024)], in which we pointed out…

Astrophysics of Galaxies · Physics 2025-01-27 Domenico Giordano , Pierluigi Amodio , Felice Iavernaro , Francesca Mazzia

I discuss the conformal approach to the numerical simulation of radiating isolated systems in general relativity. The method is based on conformal compactification and a reformulation of the Einstein equations in terms of rescaled…

General Relativity and Quantum Cosmology · Physics 2022-09-21 Sascha Husa

An analytic solution has been found in the Roche approximation for the axially symmetric structure of a hydrostatically equilibrium atmosphere of a neutron star produced by collapse. A hydrodynamic (quasione-dimensional) model for the…

Astrophysics · Physics 2009-11-10 V. S. Imshennik , K. V. Manukovskii

Aqueous foams and a wide range of related systems are believed to coarsen by gas diffusion between neighboring domains into a statistically self-similar scaling state, after the decay of initial transients, such that dimensionless size and…

Soft Condensed Matter · Physics 2023-09-19 Anthony T. Chieco , Douglas J. Durian

Context: The gas density structure of the cold molecular phase of the interstellar medium is the main controller of star formation. Aims: A theoretical framework is proposed to describe the structural content of the density field in…

Fluid Dynamics · Physics 2023-08-15 Fabien Thiesset , Christoph Federrath

Fractional differential equations provide a tractable mathematical framework to describe anomalous behavior in complex physical systems, yet they introduce new sensitive model parameters, i.e. derivative orders, in addition to model…

Numerical Analysis · Mathematics 2018-06-05 Ehsan Kharazmi , Mohsen Zayernouri

Context: The thermal instability is one of the dynamical agents for turbulence in the diffuse interstellar medium, where both, turbulence and thermal instability interact in a highly non-linear manner. Aims: We study basic properties of…

Astrophysics of Galaxies · Physics 2015-05-19 D. Seifried , W. Schmidt , J. C. Niemeyer

We use standard polynomial expansion technique to show the existence of a relation between polytropic model and the description of gas spheres at finite temperature. A numerical analysis is made concerning the obtained perturbative…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-24 Claudio M. G. de Sousa , Evandro A. de Araujo