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In previous work, two of us have proposed a model of inflationary magnetogenesis based on a rolling auxiliary field able both to account for the magnetic fields inferred by the (non) observation of gamma-rays from blazars, and to start the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Chiara Caprini , Maria Chiara Guzzetti , Lorenzo Sorbo

We propose a natural scenario for the cosmological inflation with the non-minimal coupling term invoking compact hyperbolic extra dimensions. Thanks to the unique mathematical properties of compact hyperbolic space, the large volume of…

High Energy Physics - Phenomenology · Physics 2011-03-22 Yoonbai Kim , Seong Chan Park

We show that maximally helical hypermagnetic fields produced during pseudoscalar inflation can generate the observed baryon asymmetry of the universe via the B+L anomaly in the Standard Model. We find that most of the parameter space of…

High Energy Physics - Theory · Physics 2015-11-11 Mohamed M. Anber , Eray Sabancilar

Helical magnetic fields are injected into the cosmic medium during cosmological baryogenesis and can potentially provide a useful probe of the early universe. We construct a model to study the injection process during a first order phase…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Yifung Ng , Tanmay Vachaspati

Holographic considerations may provide a glimpse of quantum gravity beyond what is currently accessible by other means. Here we apply holography to inflationary cosmology. We argue that the appropriate holographic bound on the total entropy…

High Energy Physics - Theory · Physics 2007-05-23 Andreas Albrecht , Nemanja Kaloper , Yong-Seon Song

Numerical solutions of Einstein, scalar, and gauge field equations are found for static and inflating defects in a higher-dimensional spacetime. The defects have $(3+1)$-dimensional core and magnetic monopole configuration in $n=3$ extra…

High Energy Physics - Theory · Physics 2009-11-10 Inyong Cho , Alexander Vilenkin

It is shown that the standard cosmological model predicts {\it ab initio} generation of large-scale but very small-amplitude cosmic magnetic fields at the epoch of recombination of the primeval plasma. Matter velocities dominated by…

Astrophysics · Physics 2007-05-23 Craig J. Hogan

The spectrum of energy density fluctuations, baryon asymmetry, and coherent large-scale magnetic fields are the three observables that provide crucial information on physics at very high energies. Inflation can only provide a mechanism to…

High Energy Physics - Phenomenology · Physics 2021-09-09 Ashu Kushwaha , S. Shankaranarayanan

Mechanisms of generation of magnetic fields in the early universe which could seed the present-day large scale galactic magnetic fields, are briefly reviewed. Three possible ways to create large scale magnetic fields are discussed: breaking…

High Energy Physics - Phenomenology · Physics 2016-11-23 A. D. Dolgov

In this paper, we propose a mechanism to generate large-scale magnetic fields with correlations lengths of 100 kpc. Domain walls with QCD scale internal structure form and coalesce obtaining Hubble size correlations and align nucleon spins.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michael McNeil Forbes , Ariel R. Zhitnitsky

A primordial magnetic field may be generated during an inflationary period if conformal invariance is broken. We reexamine and generalize previous results about the magnetic field produced by couplings of the form $R^n…

Astrophysics · Physics 2009-10-28 F. D. Mazzitelli , F. M. Spedalieri

The dynamical evolution of internal space-like dimensions breaks the invariance of the Maxwell's equations under Weyl rescaling of the (conformally flat) four-dimensional metric. Depending upon the number and upon the dynamics of internal…

High Energy Physics - Phenomenology · Physics 2009-10-31 Massimo Giovannini

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

Magnetic fields are present on all scales in the Universe. While we understand the processes which amplify the fields fairly well, we do not have a "natural" mechanism to generate the small initial seed fields. By using fully relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-18 Ellie Nalson , Adam J. Christopherson , Karim A. Malik

It is usually assumed that when Weyl invariance is unbroken in the electromagnetic sector, the energy density of primordial magnetic fields will redshift as radiation. Here we show that primordial magnetic fields do not exhibit…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-22 Takeshi Kobayashi , Martin S. Sloth

The evolution of magnetic fields is studied using simulations of forced helical turbulence with strong imposed shear. After some initial exponential growth, the magnetic field develops a large scale travelling wave pattern. The resulting…

Astrophysics · Physics 2009-10-31 Axel Brandenburg , Alberto Bigazzi , Kandaswamy Subramanian

We study the characteristic size and shape of idealized blazar-induced cascade halos in the $1-100 \, {\rm GeV}$ energy range assuming various non-helical and helical configurations for the intergalactic magnetic field (IGMF). While the…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Andrew J. Long , Tanmay Vachaspati

We use three-dimensional direct numerical simulations of the helically forced magnetohydrodynamic equations in spherical shell segments in order to study the effects of changes in the geometrical shape and size of the domain on the growth…

Astrophysics · Physics 2010-01-15 Dhrubaditya Mitra , Reza Tavakol , Axel Brandenburg , David Moss

The interrelation between the generation of large-scale electric fields and that of large-scale magnetic fields due to the breaking of the conformal invariance of the electromagnetic field in inflationary cosmology is studied. It is shown…

Astrophysics · Physics 2009-06-23 Kazuharu Bamba

Cosmological vector fields are central to many early-Universe phenomena, including inflationary dynamics, primordial magnetogenesis, and dark-matter scenarios. However, constructing models able to generate cosmological magnetic fields while…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-29 H. V. Ragavendra , Gianmassimo Tasinato , L. Sriramkumar