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Related papers: Inflationary Magnetogenesis without the Strong Cou…

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We investigate in more depth the issue of backreaction in models that attempt at generating cosmological magnetic fields at inflation. By choosing different, physically motivated, parametrisations, we are able to isolate the core of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-14 Federico R. Urban

We explore cosmological magnetogenesis in the post-inflationary universe, when the inflaton oscillates around its potential minimum and the universe is effectively dominated by cold matter. During this epoch prior to reheating, large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-29 Takeshi Kobayashi

We study the generation of magnetic fields in the Higgs inflation model with the axial coupling in order to break the conformal invariance of the Maxwell action and produce strong magnetic fields. We consider radiatively corrected Higgs…

General Relativity and Quantum Cosmology · Physics 2021-08-17 Mehran Kamarpour

While during inflation a phase of increasing gauge coupling allows for a scale-invariant hyperelectric spectrum, when the coupling decreases a flat hypermagnetic spectrum can be generated for typical wavelengths larger than the effective…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Massimo Giovannini

Although inflation is a natural candidate to generate the lengths of coherence of magnetic fields needed to explain current observations, it needs to break conformal invariance of electromagnetism to obtain significant magnetic amplitudes.…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 Federico Agustin Membiela

When the gauge fields have derivative couplings to scalars, like in the case of the relativistic theory of Van der Waals (or Casimir-Polder) interactions, conformal invariance is broken but the magnetic and electric susceptibilities are not…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-23 Massimo Giovannini

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

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}…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 Ramkishor Sharma , Kandaswamy Subramanian , T. R. Seshadri

We propose a novel scenario to generate primordial magnetic fields during inflation induced by an oscillating coupling of the electromagnetic field to the inflaton. This resonant mechanism has two key advantages over previous proposals.…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-22 Christian T. Byrnes , Lukas Hollenstein , Rajeev Kumar Jain , Federico R. Urban

We point out that a successful inflationary magnetogenesis could be realised if we break the local U(1) gauge symmetry during inflation. The effective electric charge is fixed as a fundamental constant, which allows us to obtain an almost…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Guillem Domènech , Chunshan Lin , Misao Sasaki

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 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 study the primordial magnetic field generated by the simple model $f^2 FF$ in Starobinsky, $R^2$-inflationary, model. The scale invariant PMF is achieved at relatively high power index of the coupling function, $\left| \alpha \right|…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-21 Anwar Saleh AlMuhammad

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

Primordial magnetogenesis is an intriguing possibility to explain the origin of intergalactic magnetic fields (IGMFs). However, the baryon isocurvature problem has recently been pointed out, ruling out all magnetogenesis models operating…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-08 Kazuki Yanagihara , Fumio Uchida , Tomohiro Fujita , Shinji Tsujikawa

In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-26 Peter Adshead , John T. Giblin , Timothy R. Scully , Evangelos I. Sfakianakis

We study the generation of helical magnetic fields during inflation by considering a model which does not suffer from strong coupling or large back-reaction. Electromagnetic conformal invariance is broken only during inflation by coupling…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-16 Chiara Cecchini , Massimiliano Rinaldi

As additional perturbative degrees of freedom, it is known that magnetic fields of inflationary origin can source curvature perturbations on super-Hubble scales. By requiring the magnetic generated curvature to remain smaller than its…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Christophe Ringeval , Teruaki Suyama , Jun'ichi Yokoyama

Recent blazar observations provide growing evidence for the presence of magnetic fields in the extragalactic regions. While a natural speculation is to associate the production to inflationary physics, it has been known that magnetogenesis…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Tomohiro Fujita , Ryo Namba

We consider inflationary magnetogenesis where the conformal symmetry is broken by the term $f^2(\phi) F_{\alpha\beta} F^{\alpha\beta}$. We assume that the magnetic field power spectrum today between 0.1 and $10^4$ Mpc is a power law, with…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-20 Tommi Markkanen , Sami Nurmi , Syksy Rasanen , Vincent Vennin