English
Related papers

Related papers: An analytic solar model physical principles and ma…

200 papers

Helioseismology studies the structure and dynamics of the Sun's interior by observing oscillations on the surface. These studies provide information about the physical processes that control the evolution and magnetic activity of the Sun.…

Solar and Stellar Astrophysics · Physics 2015-05-27 Alexander G. Kosovichev

The present work represents a step to deal with stellar structure using a pure geometric approach. A geometric field theory is used to construct a model for a spherically symmetric configuration. The model obtained can be considered as a…

General Relativity and Quantum Cosmology · Physics 2011-09-27 M. I. Wanas , Samah A. Ammar

Context: Solar active regions (ARs) are key manifestations of the Sun's magnetic activity, displaying diverse spatial and temporal characteristics. Their formation and evolution play a crucial role in understanding the solar dynamo and…

Solar and Stellar Astrophysics · Physics 2025-08-06 M. Švanda , J. Jurčák , M. Schmassmann

The {\em hydrodynamic} approach to a continuum mechanical description of granular behavior is reviewed and elucidated. By considering energy and momentum conservation simultaneously, the general formalism of {\em hydrodynamics} provides a…

Soft Condensed Matter · Physics 2012-06-14 Yimin Jiang , Mario Liu

In this paper we formulate the theory of nonlinear elasticity in a geometrically intrinsic manner using exterior calculus and bundle-valued differential forms. We represent kinematics variables, such as velocity and rate-of-strain, as…

Mathematical Physics · Physics 2023-08-09 Ramy Rashad , Andrea Brugnoli , Federico Califano , Erwin Luesink , Stefano Stramigioli

We investigate the mathematical structure of unit systems and the relations between them. Looking over the entire set of unit systems, we can find a mathematical structure that is called preorder (or quasi-order). For some pair of unit…

General Physics · Physics 2016-03-24 Masao Kitano

A non-Fourier thermal transport regime characterizes the heat conduction in solids with internal structure. Several thermodynamic theories attempt to explain the separation from the Fourier regime in such kind of systems. Here we develop a…

Classical Physics · Physics 2021-06-03 R. E. Gonzalez-Narvaez , M. López de Haro , F. Vázquez

We derive the equations of celestial mechanics governing the variations of the orbital elements under a stochastic perturbation generalizing the classical Gauss equations. Explicit formulas are given for the semi-major axis, the…

Earth and Planetary Astrophysics · Physics 2015-11-04 Frédéric Pierret

The overall framework for the study of solar convection and oscillations is the spherically symmetric component of solar structure. I discuss those properties of the solar interior which depend on convection and other possible…

Astrophysics · Physics 2016-01-27 J. Christensen-Dalsgaard

The Sun constitutes an excellent laboratory of fundamental physics. With the advent of helioseismology, we were able to probe its internal layers with unprecedented precision. However, the current state of solar modelling is still stained…

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive…

Solar and Stellar Astrophysics · Physics 2015-06-15 Regner Trampedach , Martin Asplund , Remo Collet , Åke Nordlund , Robert F. Stein

Thermodynamics is accepted as a universal truth, encompassing all macroscopic objects. Therefore, it is surprising to find that, within our current understanding, the photovoltaic effect has so far eluded the first and second laws of…

Statistical Mechanics · Physics 2020-12-22 Ido Frenkel , Avi Niv

The analysis of databases of photographic images of the Sun (obtained in region of soft x-ray) by means of a method of multilevel dynamical contrasting, has shown presence of skeletal structures of the Sun as outside (chromo-sphere flashes…

Astrophysics · Physics 2009-06-23 Valentin. A. Rantsev-Kartinov

Sunspots are of basic interest in the study of the Sun. Their relevance ranges from them being an activity indicator of magnetic fields to being the place where coronal mass ejections and flares erupt. They are therefore also an important…

Solar and Stellar Astrophysics · Physics 2018-05-24 Illa R. Losada , Jörn Warnecke , Kolja Glogowski , Markus Roth , Axel Brandenburg , Nathan Kleeorin , Igor Rogachevskii

The pivotal point of the paper is to discuss the behavior of temperature, pressure, energy density as a function of volume along with determination of caloric EoS from following two model: $w(z)=w_{0}+w_{1}\ln(1+z)$ & $…

General Physics · Physics 2015-03-09 Sridip Pal , Ritabrata Biswas

We present some analytical solutions to the Einstein equations, describing radiating collapsing spheres in the diffusion approximation. Solutions allow for modeling physical reasonable situations. The temperature is calculated for each…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Herrera , A. Di Prisco , J. Ospino

The spatial variation of physical quantities, such as the mass density, across solar atmospheric waveguides governs the timescales and spatial scales for wave damping and energy dissipation. The direct measurement of the spatial…

Solar and Stellar Astrophysics · Physics 2015-10-07 I. Arregui , R. Soler , A. Asensio Ramos

The role of the algebraic method has long been understood in shedding light on the topological structure of sets. However, when the set is a simplicial complex and host to a dynamical process, in particular the trajectory of a canonically…

Statistical Mechanics · Physics 2007-05-23 David ford

An overview of some analytical approaches to the computation of the structural and thermodynamic properties of single component and multicomponent hard-sphere fluids is provided. For the structural properties, they yield a thermodynamically…

Statistical Mechanics · Physics 2008-07-18 M. Lopez de Haro , S. B. Yuste , A. Santos

We introduce and study a class of active matter models in which we keep track of fuel (stored energy) consumption. They are by construction, thermodynamically consistent. Using these models it is possible for us to observe and follow how…

Soft Condensed Matter · Physics 2025-07-22 Tanniemola B. Liverpool , Kristian K. Müller-Nedebock , Xichen Chao , Chang Yuan