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In this paper, the generation of magnetic fields in a nonuniformly rotating layer of finite thickness of an electrically conducting fluid by thermomagnetic (TM) instability. This instability arises due to the temperature gradient $\nabla…

Fluid Dynamics · Physics 2021-04-23 M. I. Kopp , K. N. Kulik , A. V. Tur , V. V. Yanovsky

The Parker instability, a Rayleigh-Taylor like instability of thermal gas supported against gravity by magnetic fields and cosmic rays, is thought to be dynamically important for galaxy evolution, possibly promoting molecular cloud…

Astrophysics of Galaxies · Physics 2020-03-25 Evan Heintz , Chad Bustard , Ellen Zweibel

We present preliminary results of Particle-In-Cell simulations of magnetic turbulence production by isotropic cosmic-ray ions streaming upstream of supernova remnant shocks. The studies aim at testing the MHD predictions by Bell (2004,…

Astrophysics · Physics 2008-11-26 Jacek Niemiec , Martin Pohl

The origin of negative pressure fluid (the dark energy) is investigated in the quantum model of the homogeneous, isotropic and closed universe filled with a uniform scalar field and a perfect fluid which defines a reference frame. The…

General Relativity and Quantum Cosmology · Physics 2008-12-19 V. E. Kuzmichev , V. V. Kuzmichev

Galactic cosmic rays are believed to be mostly accelerated at supernova shocks. However, the interstellar magnetic field is too weak to efficiently accelerate galactic cosmic rays up to the highest energies, i.e. $10^{15}$ eV. A stronger…

High Energy Astrophysical Phenomena · Physics 2016-03-16 Maria Victoria del Valle , Alexandre Lazarian , Reinaldo Santos-Lima

We consider the evolution of electromagnetic fields coupled to conduction currents during the reheating era after inflation, and prior to the establishing of the proton-electron plasma. We assume that the currents may be described by second…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Esteban Calzetta , Alejandra Kandus

The chiral magnetic effect emerges from a miroscopic level, and its interesting consequences have been discussed in the dynamics of the early universe, neutron stars and quark-gluon plasma. An instability is caused by anomalous electric…

High Energy Astrophysical Phenomena · Physics 2019-03-01 Yasufumi Kojima , Yuri Miura

It is usually believed that the geo-dynamo of the Earth or more generally of other planets, is created by the convective fluid motions inside their molten cores. An alternative to this thermal or compositional convection can however be…

Fluid Dynamics · Physics 2016-08-16 P. Le Gal , L. Lacaze , S. Le Dizès

Magnetic fields are involved in every astrophysical process on every scale: from planetary and stellar interiors to neutron stars, stellar wind bubbles and supernova remnants; from the interstellar medium in galactic disks, nuclei, spiral…

The role of turbulence in various astrophysical settings is reviewed. Among the differences to laboratory and atmospheric turbulence we highlight the ubiquitous presence of magnetic fields that are generally produced and maintained by…

Solar and Stellar Astrophysics · Physics 2015-03-13 Axel Brandenburg , Aake Nordlund

In this work, we study the effect of a magnetic field on the growth of cosmological perturbations. We develop a mathematical consistent treatment in which a perfect fluid and a uniform magnetic field evolve together in a Bianchi I universe.…

General Relativity and Quantum Cosmology · Physics 2019-11-19 Federico Di Gioia , Giovanni Montani

We discuss a problem about magnetic collapse as a possible process for singularity formation of the magnetic field in a finite time within ideal magneto-hydrodynamics for incompressible fluids. This process is very important from the point…

Solar and Stellar Astrophysics · Physics 2022-02-17 E. A. Kuznetsov , E. A. Mikhailov

In the present-day universe, magnetic fields play such essential roles in star formation as angular momentum transport and outflow driving, which control circumstellar disc formation/fragmentation and also the star formation efficiency.…

Astrophysics of Galaxies · Physics 2022-12-28 Kenji Eric Sadanari , Kazuyuki Omukai , Kazuyuki Sugimura , Tomoaki Matsumoto , Kengo Tomida

The nonlinear propagation of internal gravity waves in the weakly ionized, incompressible Earth's ionosphere is studied using the fluid theory approach. Previous theory in the literature is advanced by the effects of the terrestrial…

Atmospheric and Oceanic Physics · Physics 2022-04-06 T. D. Kaladze , A. P. Misra , A. Roy , D. Chatterjee

Cosmic rays (CRs) leave their sources mainly along the local magnetic field; in doing so they excite both resonant and nonresonant modes through streaming instabilities. The excitation of these modes leads to enhanced scattering and in turn…

High Energy Astrophysical Phenomena · Physics 2021-06-10 Benedikt Schroer , Oreste Pezzi , Damiano Caprioli , Colby Haggerty , Pasquale Blasi

In this paper, we analyze the stability of a homogeneous self-gravitating plasma, having a non-zero resistivity. This study provides a generalization of the Jeans paradigm for determining the critical scale above which gravitational…

High Energy Astrophysical Phenomena · Physics 2015-03-19 Daniela Pugliese , Nakia Carlevaro , Massimiliano Lattanzi , Giovanni Montani , Riccardo Benini

We study the linear evolution of magnetised cosmological perturbations in the post-recombination epoch. Using full general relativity and adopting the ideal magnetohydrodynamic approximation, we refine and extend the previous treatments.…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Dimitra Tseneklidou , Christos G. Tsagas , John D. Barrow

Non-linear electrodynamics coupled to general relativity is investigated. In general relativity, it is observed that the expansion of the universe is accelerating if the source of the gravitational field is the non-linear electromagnetic…

General Relativity and Quantum Cosmology · Physics 2018-10-05 Gauranga C. Samanta , Shantanu K. Biswal , Kazuharu Bamba

Kinetic diffusion of cosmic rays ahead of perpendicular shocks induces charge non-neutrality, which is mostly, yet not completely, screened by the bulk plasma via polarization drift current. Hydrodynamic shear instabilities as well as…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Maxim Lyutikov

Shock waves constitute discontinuities in matter which are relevant in studying the plasma behaviour in astrophysical scenarios and in heavy-ion collision. They can produce conical emission in relativistic collisions and are also thought to…

High Energy Astrophysical Phenomena · Physics 2013-09-03 Ritam Mallick , Stefan Schramm