English
Related papers

Related papers: Magnetogenesis from isocurvature initial condition…

200 papers

We present a method for the study of second-order superhorizon perturbations in multi field inflationary models with non trivial kinetic terms. We utilise a change of coordinates in field space to separate isocurvature and adiabatic…

Astrophysics · Physics 2008-11-26 Gerasimos Rigopoulos

We study the generation of magnetic fields during inflation making use of a coupling of the inflaton and moduli fields to electromagnetism via the photon kinetic term, and assuming that the coupling is an increasing function of time. We…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-02 Hossein Bazrafshan Moghaddam , Evan McDonough , Ryo Namba , Robert H. Brandenberger

Low energy effective field theories motivated by string theory will likely contain several scalar moduli fields which will be relevant to early Universe cosmology. Some of these fields are expected to couple with non-standard kinetic terms…

Astrophysics · Physics 2009-11-07 Fabrizio Di Marco , Fabio Finelli , Robert Brandenberger

We present an analytical derivation of the Sachs Wolfe effect sourced by a primordial magnetic field. In order to consistently specify the initial conditions, we assume that the magnetic field is generated by a causal process, namely a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Camille Bonvin , Chiara Caprini

We investigate the influence of cosmic magnetic fields on gravitational wave perturbations, and find exact solutions on large scales. We show that a large-scale magnetic field can generate large-scale non-decaying gravitational waves. In…

Astrophysics · Physics 2009-11-06 Roy Maartens , Christos Tsagas , Carlo Ungarelli

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 origin of magnetic fields observed on both astrophysical and cosmological scales is a compelling problem that has the potential to shed light on the early Universe. We analytically investigate inflationary magnetogenesis in scenarios…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-08 Bill Atkins , Debika Chowdhury , Alisha Marriott-Best , Gianmassimo Tasinato

We study the generation of magnetic field in the primordial plasma of the standard model (SM) particles at temperature $T>80$~TeV much higher than the electroweak scale. It is assumed that there is an excess number of right-handed electrons…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Jitesh R. Bhatt , Arun Kumar Pandey

The initial conditions on the anisotropies of the stochastic gravitational-wave background of cosmological origin (CGWB) largely depend on the mechanism that generates the gravitational waves. Since the CGWB is expected to be non-thermal,…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-15 Lorenzo Valbusa Dall'Armi , Alina Mierna , Sabino Matarrese , Angelo Ricciardone

We present for the first time kinetic 2D Vlasov-Fokker-Planck simulations, including both self-consistent magnetic fields and ablating ion outflow, of a planar ablating foil subject to nonuniform laser irradiation. Even for small hall…

Plasma Physics · Physics 2018-09-12 D. W. Hill , R. J. Kingham

We reexamine generation of the primordial magnetic fields, at temperature $T>80$TeV, by applying a consistent kinetic theory framework which is suitably modified to take the quantum anomaly into account. The modified kinetic equation can…

General Relativity and Quantum Cosmology · Physics 2016-09-01 Arun Kumar Pandey , Jitesh R. Bhatt

In this Letter we reanalyse the question of the origin of magnetic fields during the electroweak phase transition. We show that their formation is intimately connected to some semiclassical configurations of the gauge fields, such as…

High Energy Physics - Phenomenology · Physics 2009-10-30 Dario Grasso , Antonio Riotto

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

The most general initial conditions of CMB anisotropies, compatible with the presence of pre-equality magnetic fields, are derived. When the plasma is composed by photons, baryons, electrons, CDM particles and neutrinos, the initial data of…

Astrophysics · Physics 2008-11-26 Massimo Giovannini , Kerstin E. Kunze

Magnetic fields may have been generated in the electroweak phase transition through spontaneous symmetry breaking or through the subsequent dynamical evolution of semiclassical field configurations. Here I demonstrate explicitly how…

High Energy Physics - Phenomenology · Physics 2009-10-30 Ola Tornkvist

Sufficiently large seeds for generating the observed (inter)galactic magnetic fields emerge naturally in string cosmology from the amplification of electromagnetic vacuum fluctuations due to a dynamical dilaton background. The success of…

High Energy Physics - Theory · Physics 2009-10-28 M. GasperinI , M. Giovannini , G. Veneziano

It is shown that flows in precessing cubes develop at certain parameters large axisymmetric components in the velocity field which are large enough to either generate magnetic fields by themselves, or to contribute to the dynamo effect if…

Fluid Dynamics · Physics 2019-05-22 O. Goepfert , A. Tilgner

We develop a theory of self-resonance after inflation. We study a large class of models involving multiple scalar fields with an internal symmetry. For illustration, we often specialize to dimension 4 potentials, but we derive results for…

High Energy Physics - Theory · Physics 2017-08-15 Mark P. Hertzberg , Johanna Karouby , William G. Spitzer , Juana C. Becerra , Lanqing Li

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…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Orfeu Bertolami , Maria Margarida Lima , Filipe C. Mena

Excitation of spin wave modes of a vortex-state magnetic dot by an out-of-plane oscillating magnetic field is studied numerically in the presence of a static in-plane magnetic field. It is shown, that the application of the in-plane static…

Mesoscale and Nanoscale Physics · Physics 2016-04-26 Yan Liu , Yan Zhou , P. Dürrenfeld , Y. Yin , D. W. Wang , A. N. Slavin , A. Ruotolo