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Related papers: A Holographic Bound on Cosmic Magnetic Fields

200 papers

We explore some particle physics implications of the growing evidence for a helical primordial magnetic field (PMF). From the interactions of magnetic monopoles and the PMF, we derive an upper bound on the monopole number density, $n(t_0) <…

High Energy Physics - Phenomenology · Physics 2015-05-27 Andrew J. Long , Tanmay Vachaspati

In this work we consider quantum electromagnetic fields in an expanding universe. We start by reviewing the difficulties found when trying to impose the Lorenz condition in a time-dependent geometry. Motivated by this fact, we explore the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Jose Beltran Jimenez , Antonio L. Maroto

It is shown that holographic cosmology implies an evolving Hubble radius $c^{-1}\dot{R}_H = -1 + 3\Omega_m$ in the presence of a dimensionless matter density $\Omega_m$ scaled to the closure density $3H^2/8\pi G$, where $c$ denotes the…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Maurice H. P. M. van Putten

Observationally, magnetic fields reach equipartition with thermal energy and cosmic rays in the interstellar medium of disk galaxies such as the Milky Way. However, thus far cosmological simulations of the formation and evolution of…

Astrophysics of Galaxies · Physics 2015-06-18 R. Pakmor , F. Marinacci , V. Springel

In QCD, the strengths of the large scale temperature dependent chromomagnetic, $B_3, B_8$, and usual magnetic, $H$, fields spontaneously generated in quark-gluon plasma after the deconfinement phase transition (DPT), are estimated. The…

High Energy Physics - Phenomenology · Physics 2018-12-05 V. Skalozub , P. Minaev

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…

High Energy Physics - Phenomenology · Physics 2019-05-22 Ariel R. Zhitnitsky

Magnetic fields are ubiquitous in the universe and an important component of the interstellar medium. It is crucial to accurately model and understand their properties in different environments and across all mass ranges of galaxies to…

Astrophysics of Galaxies · Physics 2025-12-22 Maria Werhahn , Rüdiger Pakmor , Rebekka Bieri , Freeke van de Voort , Rosie Y. Talbot , Volker Springel

Recent high-angular-resolution (up to 0.7") dust polarization observations toward star forming regions are summarized. With the Sub-Millimeter Array, the emission from the dense structures is traced and resolved. The detected magnetic field…

Astrophysics of Galaxies · Physics 2012-02-22 Ya-Wen Tang , Patrick M. Koch , Paul T. P. Ho

The efficient release of magnetic energy in astrophysical plasmas, such as during solar flares, can in principle be achieved through magnetic diffusion, at a rate determined by the associated electric field. However, attempts at measuring…

We consider the evolution of primordial magnetic fields generated during cosmological, electroweak or QCD, phase transitions. We assume that the magnetic field generation can be described as an injection of magnetic energy to cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-24 Tina Kahniashvili , Alexander G. Tevzadze , Axel Brandenburg , Andrii Neronov

We give a pedagogical review of a mechanism through which long wave length photons can become massive during inflation. Our account begins with a discussion of the period of exponentially rapid expansion known as inflation. We next describe…

Astrophysics · Physics 2009-11-07 T. Prokopec , R. P. Woodard

This paper concerns the generation and evolution of the cosmological (large-scale $\sim Mpc$) magnetic fields in an inflationary universe. The universe during inflation is represented by de Sitter space-time. We started with the Maxwell…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Zuxiang Dai

The presence of magnetic fields in the early universe affects the cosmological processes, leading to the distinct signature, which allows constraining their properties and the genesis mechanisms. In this study, we revisit the method to…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-13 Ashu Kushwaha , Teruaki Suyama

Strong magnetic fields are observed in a substantial fraction of upper main sequence stars and white dwarfs. Many such stars are observed to exhibit photometric modulations as the magnetic poles rotate in and out of view, which could be a…

Solar and Stellar Astrophysics · Physics 2023-02-22 Jim Fuller , Stephane Mathis

The values of electrical conductivity of plasma of stars with a magnetic field or moving in the magnetic field of the other component in a binary system could be of significant interest, since they are useful for the study of thermal…

The Galactic magnetic field is important in the dynamics of our Galaxy. It is believed to play a role in star formation and influence the structure of the Galaxy. In order to understand how the Galactic magnetic field originally formed or…

Astrophysics of Galaxies · Physics 2010-12-15 Kyle Rae , Jo-Anne Brown

An analytical model predicting the growth rates, the absolute growth times and the saturation values of the magnetic field strength within galactic haloes is presented. The analytical results are compared to cosmological MHD simulations of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Alexander M. Beck , Harald Lesch , Klaus Dolag , Hanna Kotarba , Annette Geng , Federico A. Stasyszyn

This paper examines the generation of seed magnetic fields due to the growth of cosmological perturbations. In the radiation era, different rates of scattering from photons induce local differences in the ion and electron density and…

Astrophysics · Physics 2008-11-26 E. R. Siegel , J. N. Fry

The generation of large-scale magnetic fields is studied in dilaton electromagnetism in inflationary cosmology, taking into account the dilaton's evolution throughout inflation and reheating until it is stabilized with possible entropy…

Astrophysics · Physics 2008-11-26 Kazuharu Bamba , J. Yokoyama

Some common properties of helical magnetic fields in decaying and driven turbulence are discussed. These include mainly the inverse cascade that produces fields on progressively larger scales. Magnetic helicity also restricts the evolution…

Astrophysics · Physics 2007-05-23 Axel Brandenburg