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The He3 abundance is not constrained by helioseismic data. Mixing of He3 inside the solar core by processes not included in the solar standard model (SSM) has been recently proposed as possible solution to the solar neutrino problem. We…

Astrophysics · Physics 2009-12-30 V. Berezinsky , G. Fiorentini , M. Lissia

We explore the effect of some simple perturbations on three chaotic models proposed to describe large scale solar behavior via the solar dynamo theory: the Lorenz and the Rikitake systems, and a Van der Pol-Duffing oscillator. Planetary…

Chaotic Dynamics · Physics 2023-12-15 Juan M. Muñoz , Alexandre Wagemakers , Miguel A. F. Sanjuán

We consider quasi-geostrophic (Q-G) models in two- and three-layers that are useful in theoretical studies of planetary atmospheres and oceans. In these models, the streamfunctions are given by (1+2) partial differen- tial systems of…

Analysis of PDEs · Mathematics 2017-12-01 Sameerah Jamal

For the nonlinear Dirac equation with scalar self-interaction (the Soler model) in three spatial dimensions, we consider the linearization at solitary wave solutions and find the invariant spaces which correspond to different spherical…

Analysis of PDEs · Mathematics 2024-12-31 Nabile Boussaïd , Andrew Comech , Niranjana Kulkarni

In this work we use solar observations with the ALMA radio telescope at the wavelength of 1.21 mm. The aim of the analysis is to improve understanding of the solar chromosphere, a dynamic layer in the solar atmosphere between the…

Solar and Stellar Astrophysics · Physics 2018-12-19 R. Brajša , D. Sudar , I. Skokic , A. O. Benz , M. Kuhar , A. Kobelski , S. Wedemeyer , S. M. White , H. -G. Ludwig , M. Temmer , S. H. Saar , C. L. Selhorst

The quantification of all possible waves and instabilities in a given system is of paramount importance, and knowledge of the full magnetohydrodynamic (MHD) spectrum allows one to predict the (in)stability of a given equilibrium state. This…

Solar and Stellar Astrophysics · Physics 2021-10-04 Niels Claes , Rony Keppens

A differential emission measure (DEM) method is used to evaluate the relationship of the electron density and temperature before and after a coronal rain event during an active sun over the period from 20:10 UT on October 6 to 02:10 on…

Solar and Stellar Astrophysics · Physics 2021-10-05 Z. M. Vashalomidze , T. V. Zaqarashvili , V. D. Kukhianidze

The solar interior is probed by the properties of the Sun's acoustic oscillations (p-modes) observed on the solar surface. The frequencies of these p-modes measured in the last three decades show long term variation similar to the 11 year…

Solar and Stellar Astrophysics · Physics 2026-04-23 Rekha Jain , Akash Kumar , Sushanta C. Tripathy

We present a 3-dimensional (3D) numerical solver of the linearized compressible Euler equations (GALE -- Global Acoustic Linearized Euler), used to model acoustic oscillations throughout the solar interior. The governing equations are…

Solar and Stellar Astrophysics · Physics 2021-03-01 Andrey M. Stejko , Alexander G. Kosovichev , Nagi N. Mansour

Hydrostatic equilibrium and energy conservation determine the conditions in the gravitationally stabilized solar fusion reactor. We assume a matter density distribution varying non- linearly through the central region of the Sun. The…

Astrophysics · Physics 2011-03-17 H. J. Haubold , A. M. Mathai

Analyses of a 3D simulation of the upper layers of a solar convective envelope provide constraints on the physical quantities which enter the theoretical formulation of a stochastic excitation model of solar p modes, for instance the…

Astrophysics · Physics 2009-11-07 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

We present a technique to construct a spectropolarimetrically accurate magneto-hydrostatic model of a large-scale solar magnetic field concentration, mimicking a sunspot. Using the constructed model we perform a simulation of acoustic wave…

Solar and Stellar Astrophysics · Physics 2015-04-10 D. Przybylski , S. Shelyag , P. S. Cally

The aim of this work is to provide new insights on the dynamics associated to the resonances which arise as a consequence of the coupling of the effect due to the oblateness of the Earth and the Solar Radiation Pressure (SRP) effect for an…

Earth and Planetary Astrophysics · Physics 2022-12-14 Roberto Paoli

Spherical systems with polytropic equations of state are of great interest in astrophysics. They are widely used to describe neutron stars, red giants, white dwarfs, brown dwarfs, main sequence stars, galactic halos, and globular clusters…

General Relativity and Quantum Cosmology · Physics 2013-09-24 P. H. Nguyen , J. F. Pedraza

Recent observation of large amplitude Langmuir waveforms during a Type III event in the solar wind have been interpreted as the signature of the electrostatic decay of beam-driven Langmuir waves. This mechanism is thought to be a first step…

Solar and Stellar Astrophysics · Physics 2013-01-23 Pierre Henri , Francesco Califano , Carine Briand , André Mangeney

The solar activity provides an important impact not only on the intensity of cosmic rays but also on the earth environment. In this paper, a coupled oscillator model is proposed to explain the solar activity. By this model the 89 year…

Solar and Stellar Astrophysics · Physics 2018-06-26 Yasushi Muraki

A new electronic structure model is developed in which the ground state energy of a molecular system is given by a Hartree-Fock-like expression with parametrized one- and two-electron integrals over an extended (minimal + polarization) set…

Chemical Physics · Physics 2014-02-11 Dimitri N. Laikov

In this paper we present a comprehensive theoretical description of molecular spectral converters in the specific context of Luminescent Solar Concentrators (LSCs). The theoretical model is an extension to a three-level system interacting…

Quantum Physics · Physics 2009-07-22 Petra F. Scudo , Luigi Abbondanza , Roberto Fusco

The temperature and density conditions in the magnetized photosphere and chromosphere of the Sun lead to a very small degree of atomic ionization. In addition, at particular height, the magnetic field may be strong enough to give rise to a…

Solar and Stellar Astrophysics · Physics 2015-04-08 Elena Khomenko

We theoretically study a nanospaser system, which consists of a spherical silver nanoparticle embedded inside a sphere composed of dye molecules. The gain of the system, dye molecules, are described by a three-level model, where the…