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相关论文: Nearly Minimal Magnetogenesis

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The power spectrum of the cosmic microwave background from both the {\it Planck} and {\it WMAP} data exhibits a slight dip for multipoles in the range of $l= 10-30$. We show that such a dip could be the result of the resonant creation of…

宇宙学与河外天体物理 · 物理学 2016-04-13 Grant J. Mathews , Mayukh R. Gangopadhyay , Kiyotomo Ichiki , Toshitaka Kajino

Magnetic fields are observed not only in stars, but in galaxies, clusters, and even high redshift Lyman-alpha systems. In principle, these fields could play an important role in structure formation and also affect the anisotropies in the…

天体物理学 · 物理学 2009-10-31 Roy Maartens

We investigate the generation of features at large scales in the primordial power spectrum (PPS) when inflation is driven by two scalar fields. In canonical single field models of inflation, these features are often generated due to…

宇宙学与河外天体物理 · 物理学 2020-08-19 Matteo Braglia , Dhiraj Kumar Hazra , L. Sriramkumar , Fabio Finelli

A physically consistent model of magnetic field generation by convection in a rotating spherical shell with a minimum of parameters is applied to the Sun. Despite its unrealistic features the model exhibits a number of properties resembling…

太阳与恒星天体物理 · 物理学 2015-06-04 R. D. Simitev , F. H. Busse

We consider a scale-invariant helical magnetic field generated during inflation. We show that, if the mean magnetic helicity density of such a field is measured, it can be used to determine a lower bound on the duration of inflation. Upper…

宇宙学与河外天体物理 · 物理学 2018-02-13 Tina Kahniashvili , Axel Brandenburg , Ruth Durrer , Alexander G. Tevzadze , Winston Yin

In the first part of this paper, we outline the construction of an inflationary cosmology in the framework where inflation is described by a universally evolving scalar field, with the Lagrangian ${\cal L}_\phi=-{1/2}(\partial\phi)^2…

天体物理学 · 物理学 2009-12-15 Ishwaree P. Neupane , Christoph Scherer

We propose a scenario of the beginning of inflation in which the non-vacuum value of the scalar field that drives inflation develops dynamically due to the non-minimal coupling to gravity. In this scenario, inflation emerges as an…

高能物理 - 唯象学 · 物理学 2016-09-06 M. V. Libanov , V. A. Rubakov , P. G. Tinyakov

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…

宇宙学与河外天体物理 · 物理学 2019-09-11 Tomohiro Fujita , Ruth Durrer

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…

宇宙学与河外天体物理 · 物理学 2015-06-22 Chiara Caprini , Lorenzo Sorbo

We suggest a new type of hill-top inflation originating from the initial conditions in the form of the microcanonical density matrix for the cosmological model with a large number of quantum fields conformally coupled to gravity. Initial…

高能物理 - 理论 · 物理学 2016-01-27 A. O. Barvinsky , A. Yu. Kamenshchik , D. V. Nesterov

We study the generation of large scale primordial magnetic fields by a cosmological phase transition during the radiation dominated era. The setting is a theory of N charged scalar fields coupled to an abelian gauge field, that undergoes a…

天体物理学 · 物理学 2007-05-23 D. Boyanovsky , H. J. de Vega , M. Simionato

We study the inflationary generation of helical magnetic fields from the Riemann coupling with the electromagnetic field. Most models in the literature introduce non-minimal coupling to the electromagnetic fields with a scalar field, hence,…

广义相对论与量子宇宙学 · 物理学 2020-11-25 Ashu Kushwaha , S. Shankaranarayanan

We study the effects of primordial magnetic fields on the inflationary potential in the context of a warm inflation scenario. The model, based on global supersymmetry with a new-inflation-type potential and a coupling between the inflaton…

高能物理 - 唯象学 · 物理学 2014-10-08 Gabriella Piccinelli , Angel Sanchez , Alejandro Ayala , Ana Julia Mizher

In this paper we show that the Universe is already strongly magnetized at very early epochs during cosmic evolution. Our calculations are based on the efficient amplification of weak magnetic seed fields, which are unavoidably present in…

宇宙学与河外天体物理 · 物理学 2014-05-09 Jacques M. Wagstaff , Robi Banerjee , Dominik Schleicher , Guenter Sigl

We present new generation mechanisms of magnetic fields in supernova remnant shocks propagating to partially ionized plasmas in the early universe. Upstream plasmas are dissipated at the collisionless shock, but hydrogen atoms are not…

高能天体物理现象 · 物理学 2022-09-08 Shuhei Kashiwamura , Yutaka Ohira

We study the generation of helical magnetic fields in a model of inflationary magnetogenesis which is free from the strong coupling and back-reaction problems. To generate helical magnetic fields, we add an $f^2 \tilde{F}^{\mu\nu}…

宇宙学与河外天体物理 · 物理学 2018-04-11 Ramkishor Sharma , Kandaswamy Subramanian , T. R. Seshadri

In this paper, we study the generation of a large scale magnetic field with amplitude of order $\mu$G in an inflationary model which has been introduced in hep-th/0310221. This inflationary model based on existence of a speed limit for…

高能物理 - 理论 · 物理学 2009-11-11 Mohammad A. Ganjali

Here we summarize our recent results of high-resolution computer simulations on the turbulent amplification of weak magnetic seed fields showing that such fields will be exponentially amplified also during the gravitational collapse…

宇宙学与河外天体物理 · 物理学 2012-02-22 Robi Banerjee , Sharanya Sur , Christoph Federrath , Dominik R. G. Schleicher , Ralf S. Klessen

We apply the effective field theory approach to quasi-single field inflation, which contains an additional scalar field with Hubble scale mass other than inflaton. Based on the time-dependent spatial diffeomorphism, which is not broken by…

高能物理 - 理论 · 物理学 2015-06-12 Toshifumi Noumi , Masahide Yamaguchi , Daisuke Yokoyama

We have tested the ability of driven turbulence to generate magnetic field structure from a weak uniform field using three dimensional numerical simulations of incompressible turbulence. We used a pseudo-spectral code with a numerical…

天体物理学 · 物理学 2009-10-31 Jungyeon Cho , Ethan T. Vishniac
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