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A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound $\sim 10^{-16}$ Gauss. Such magnetic fields can play an…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-15 Tanmay Vachaspati

We discuss a model which can generate scale-invariant helical magnetic fields on large scales ($\lesssim 1$Mpc) in the primordial universe. It is also shown that the electric conductivity becomes significant and terminates magnetogenesis…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-11 Tomohiro Fujita , Ruth Durrer

We investigate the origin and evolution of primordial electric and magnetic fields in the early universe, when the expansion is governed by a cosmological constant $\Lambda_0$. Using the gravitoelectromagnetic inflationary formalism with…

General Relativity and Quantum Cosmology · Physics 2009-04-06 Federico Agustin Membiela , Mauricio Bellini

We discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the second order.…

We consider the generation of large-scale magnetic fields in slow-roll inflation. The inflaton field is described in a supergravity framework where the conformal invariance of the electromagnetic field is generically and naturally broken.…

Astrophysics · Physics 2009-06-23 Jerome Martin , Jun'ichi Yokoyama

The origin of large-scale magnetic field in the universe is one of the greatest mysteries in modern cosmology. We present a new mechanism for generation of large-scale magnetic field, based on the power-counting renormalizable theory of…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-07 Satoshi Maeda , Shinji Mukohyama , Tetsuya Shiromizu

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

There are at present more then 30 theories about the origin of cosmic magnetic fields at galactic and intergalactic scales. Most of them rely on concepts of elementary particle physics, like phase transitions in the early Universe, string…

Astrophysics · Physics 2007-05-23 E. Battaner , H. Lesch

We study the evolution of an inflation-generated magnetic field, due to its coupling to fluid motions, during cosmological phase transitions. We find that the magnetic field stays almost unchanged on large scales, while on small scales the…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Tina Kahniashvili , Axel Brandenburg , Leonardo Campanelli , Bharat Ratra , Alexander G. Tevzadze

Cosmological phase transitions accompanied by some kind of symmetry breaking would cause the creation of topological defects and the resulting production of primordial magnetic field. Moreover, such a procedure inevitably affects the cosmic…

High Energy Physics - Phenomenology · Physics 2014-11-21 Michiyasu Nagasawa

The origin of galactic and extra-galactic magnetic fields is an unsolved problem in modern cosmology. A possible scenario comes from the idea of these fields emerged from a small field, a seed, which was produced in the early universe…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 Hector J. Hortua , Leonardo Castaneda , Juan M. Tejeiro

We consider the cosmology where some function f(G) of the Gauss-Bonnet term G is added to the gravitational action to account for the late-time accelerating expansion of the universe. The covariant and gauge invariant perturbation equations…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Baojiu Li , John D. Barrow , David F. Mota

Primordial magnetic fields are generated during inflation by considering actions that break the conformal invariance of the electromagnetic field. To break the conformal invariance, the electromagnetic fields are coupled either to the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Sagarika Tripathy , Debika Chowdhury , Rajeev Kumar Jain , L. Sriramkumar

Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with magnetic fields derived in previous works are…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-20 Kazuhiko Kojima , Kiyotomo Ichiki

The most studied mechanism of inflationary magnetogenesis relies on the time-dependence of the coefficient of the gauge kinetic term $F_{\mu\nu}\,{F}^{\mu\nu}$. Unfortunately, only extremely finely tuned versions of the model can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Chiara Caprini , Lorenzo Sorbo

Problems and perspectives concerning the existence of large-scale magnetic fields are described. Heeding observations, possible origins and implications of magnetic fields in spiral galaxies and in regular clusters are scrutinized in…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Giovannini

The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-26 Kandaswamy Subramanian

Generation of large-scale magnetic fields in inflationary cosmology is studied in teleparallelism, where instead of the scalar curvature in general relativity, the torsion scalar describes the gravity theory. In particular, we investigate a…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 Kazuharu Bamba , Chao-Qiang Geng , Ling-Wei Luo

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

In this letter, we discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the…

Astrophysics · Physics 2009-11-10 Keitaro Takahashi , Kiyotomo Ichiki , Hiroshi Ohno , Hidekazu Hanayama