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Related papers: Nearly Minimal Magnetogenesis

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We investigate the generation of large scale magnetic fields in the universe from quantum fluctuations produced in the inflationary stage. By coupling these quantum fluctuations to the dilaton field and Ricci scalar, we show that the…

Astrophysics · Physics 2008-11-26 A. Akhtari Zavareh , A. Hojjati , B. Mirza

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

We compute the contribution to the scalar metric perturbations from large-scale magnetic fields which are generated during inflation. We show that apart from the usual passive and compensated modes, the magnetic fields also contribute to…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-01 Camille Bonvin , Chiara Caprini , Ruth Durrer

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

A completely new mechanism to generate the observed amount of large-scale cosmological magnetic fields is introduced in the context of three-form inflation. The amplification of the fields occurs via fourth order dynamics of the vector…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-17 Tomi S. Koivisto , Federico R. Urban

Magnetic fields observed across cosmic scales are difficult to explain within conventional physics. A primordial origin is, thus, often assumed. While a nonminimal coupling of the inflaton with the electromagnetic field could theoretically…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Debottam Nandi , Debajyoti Choudhury

We discuss the generation of large-scale magnetic fields due to the breaking of the conformal invariance in the electromagnetic field through the $CPT$-even dimension-six Chern-Simons-like effective interaction with a fermion current in…

Astrophysics · Physics 2008-12-18 K. Bamba , C. Q. Geng , S. H. Ho

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.…

The generation of helical magnetic fields during single field inflation due to an axial coupling of the electromagnetic field to the inflaton is discussed. We find that such a coupling always leads to a blue spectrum of magnetic fields…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Rajeev Kumar Jain , Ruth Durrer , Lukas Hollenstein

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

The generation of large-scale magnetic fields is studied in inflationary cosmology. We consider the violation of the conformal invariance of the Maxwell field by dilatonic as well as non-minimal gravitational couplings. We derive a general…

Astrophysics · Physics 2009-11-11 Kazuharu Bamba , Misao Sasaki

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

We investigate the generation of magnetic fields from inflation, which occurs via breakdown of the conformal invariance of the electromagnetic (EM) field, when coupled with the Ricci scalar and the Gauss-Bonnet invariant. For the case of…

General Relativity and Quantum Cosmology · Physics 2021-04-14 Kazuharu Bamba , E. Elizalde , S. D. Odintsov , Tanmoy Paul

The existence of large-scale anisotropy can not be ruled out by the cosmic microwave background (CMB) radiation. Over the years, several models have been proposed in the context of anisotropic inflation to account for CMB's cold spot and…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Sourav Pal , Debaprasad Maity , Tuan Q. Do

We explore the generation of large-scale magnetic fields in the so-called moduli inflation. The hypercharge electromagnetic fields couple to not only a scalar field but also a pseudoscalar one, so that the conformal invariance of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-30 Kazuharu Bamba

The hot plasma above the electroweak scale contains (hyper) charged scalar particles which are coupled to Abelian gauge fields. Scalars may interact with gravity in a non-conformally invariant way and thus their fluctuations can be…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Giovannini , M. Shaposhnikov

A model of inflation is presented where the inflaton field is a complex scalar field coupled to a U(1) gauge field. Due to the axial symmetry of the potential, the inflation is driven by the radial direction while the angular field is…

High Energy Physics - Theory · Physics 2010-05-12 Razieh Emami , Hassan Firouzjahi , M. Sadegh Movahed

The simplest gauge invariant models of inflationary magnetogenesis are known to suffer from the problems of either large backreaction or strong coupling, which make it difficult to self-consistently achieve cosmic magnetic fields from…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Ricardo J. Z. Ferreira , Rajeev Kumar Jain , Martin S. Sloth

We show that, during false vacuum inflation, a primordial magnetic field can be created, sufficiently strong to seed the galactic dynamo and generate the observed galactic magnetic fields. Considering the inflaton dominated regime, our…

Astrophysics · Physics 2010-11-30 A. C. Davis , K. Dimopoulos

We suggest a new mechanism for generation of large-scale magnetic field in the hot plasma of early universe which is based on the parity violation in weak interactions and depends neither on helicity of matter turbulence resulting in the…

Astrophysics · Physics 2009-11-10 V. B. Semikoz , D. D. Sokoloff