中文
相关论文

相关论文: Metric-torsion preheating: cosmic dynamo mechanism…

200 篇论文

Convection is a fundamental mechanism for energy transport in stars and planets, playing a pivotal role in shaping their structures and evolution. The Mixing-Length Theory, a monomodal approach to convection, is widely adopted and…

太阳与恒星天体物理 · 物理学 2025-05-21 Leïla Bessila , Stéphane Mathis

The mechanisms that generate "seed" magnetic fields in our Universe and that amplify them throughout cosmic time remain poorly understood. By means of fully-kinetic particle-in-cell simulations of turbulent, initially unmagnetized plasmas,…

宇宙学与河外天体物理 · 物理学 2023-08-09 L. Sironi , L. Comisso , R. Golant

Cosmological magnetic fields in open Friedmann universes can experience superadiabatic amplification within the realm of conventional electromagnetism. This is possible mathematically, despite the conformal invariance of Maxwell's…

广义相对论与量子宇宙学 · 物理学 2015-06-05 J. D. Barrow , C. G. Tsagas , K. Yamamoto

The interstellar medium of the Milky Way and nearby disk galaxies harbours large-scale coherent magnetic fields of Microgauss strength, that can be explained via the action of a mean-field dynamo. As in our previous work, we aim to quantify…

星系天体物理 · 物理学 2020-03-18 Oliver Gressel , Detlef Elstner

Magnetic fields are hypothesized to inflate the radii of low-mass stars---defined as less massive than 0.8$M_\odot$---in detached eclipsing binaries (DEBs). We investigate this hypothesis using the recently introduced magnetic Dartmouth…

太阳与恒星天体物理 · 物理学 2013-12-09 Gregory A. Feiden , Brian Chaboyer

It has been recently argued \cite{Barvinsky:2017lfl} that the de Sitter phase in cosmology might be naturally generated as a result of dynamics of the topologically nontrivial sectors in a strongly coupled QCD-like gauge theory in expanding…

高能物理 - 唯象学 · 物理学 2019-05-22 Ariel R. Zhitnitsky

Primordial magnetic fields could explain the large-scale magnetic fields present in the Universe. Inflation and phase transitions in the early Universe could give rise to such fields with unique characteristics. We investigate the…

The origin of cosmic magnetism is an issue of fundamental importance in astrophysics. We review here some of the ideas of how large scale magnetic fields in the universe, particularly in galaxies and galaxy clusters could arise. The popular…

天体物理学 · 物理学 2009-06-23 Kandaswamy Subramanian

Magnetic fields are amplified as a consequence of galaxy formation and turbulence-driven dynamos. Galaxy mergers can potentially amplify the magnetic fields from their progenitors, making the magnetic fields dynamically important. However,…

星系天体物理 · 物理学 2021-04-05 Enrique Lopez-Rodriguez

Miniati and Bell (2011) proposed a mechanism for the generation of magnetic seeds that is based the finite resistivity of the low temperature IGM in the high redshift universe. In this model, cosmic-ray protons generated by the first…

宇宙学与河外天体物理 · 物理学 2011-10-20 Francesco Miniati , A. R. Bell

We reconstruct the 3D structure of magnetic fields, which were seeded by density perturbations during the radiation dominated epoch of the Universe and later on were evolved by structure formation. To achieve this goal, we rely on three…

宇宙学与河外天体物理 · 物理学 2019-10-21 Sebastian Hutschenreuter , Sebastian Dorn , Jens Jasche , Franco Vazza , Daniela Paoletti , Guilhem Lavaux , Torsten A. Enßlin

The existence of magnetic fields in the universe is unmistakable. They are observed at all scales from stars to galaxy clusters. However, the origin of these fields remains enigmatic. It is believed that magnetic field seeds may have…

广义相对论与量子宇宙学 · 物理学 2022-08-17 Orfeu Bertolami , Maria Margarida Lima , Filipe C. Mena

Inflation is known to produce both gravitational waves and seed magnetic fields on scales well beyond the size of the horizon. The general relativistic interaction between these two sources at the end of inflation showed a significant…

天体物理学 · 物理学 2009-11-13 Christos G. Tsagas

The emergence of large-scale magnetic fields observed in the diffuse interstellar medium is explained by a turbulent dynamo. The underlying transport coefficients have previously been extracted from numerical simulations. So far, this was…

星系天体物理 · 物理学 2015-06-11 Oliver Gressel , Abhijit Bendre , Detlef Elstner

We investigate cosmological inflationary scenarios from a gravitoelectromagnetic theory. Our work is formulated in the light of a recently introduced geometrical Weyl-Invariant scalar-tensor theory of gravity, where the nature of both the…

广义相对论与量子宇宙学 · 物理学 2018-04-10 M. Montes , José Edgar Madriz Aguilar , V. Granados

The relative growth of field and metric perturbations during preheating is sensitive to initial conditions set in the preceding inflationary phase. Recent work suggests this may protect super-Hubble metric perturbations from resonant…

高能物理 - 唯象学 · 物理学 2009-12-30 Bruce A. Bassett , Christopher Gordon , Roy Maartens , David I. Kaiser

Our understanding of the process through which magnetic fields reached their observed strengths in present-day galaxies remains incomplete. One of the advocated solutions is a turbulent dynamo mechanism that rapidly amplifies weak magnetic…

The post-inflationary evolution of inflation-produced magnetic fields, conventional or not, can change dramatically when two fundamental issues are accounted for. The first is causality, which demands that local physical processes can never…

宇宙学与河外天体物理 · 物理学 2016-06-01 Christos G. Tsagas

We report a search for new gravitational physics phenomena based on Einstein-Cartan theory of General Relativity including spacetime torsion. Starting from the parametrized torsion framework of Mao, Tegmark, Guth and Cabi, we analyze the…

广义相对论与量子宇宙学 · 物理学 2011-05-13 Riccardo March , Giovanni Bellettini , Roberto Tauraso , Simone Dell'Agnello

We simulate an isolated, magnetised Milky Way-like disc galaxy using a self-consistent model of unresolved star formation and feedback, evolving the system until it reaches statistical steady state. We show that the quasi-steady-state…

星系天体物理 · 物理学 2022-09-28 Benjamin D. Wibking , Mark R. Krumholz