English
Related papers

Related papers: Inflationary helical magnetic fields with a sawtoo…

200 papers

Inflation universally produces classical almost scale free Gaussian inhomogeneities of any light scalars. Assuming the coupling constants at the time of inflation depend on some light moduli fields, we encounter the generation of modulated…

Astrophysics · Physics 2009-11-10 Francis Bernardeau , Lev Kofman , Jean-Philippe Uzan

Inflation has the potential to seed the galactic magnetic fields observed today. However, there is an obstacle to the amplification of the quantum fluctuations of the electromagnetic field during inflation: namely the conformal invariance…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Amjad Ashoorioon , Robert B. Mann

We show that breaking of the conformal invariance of electromagnetic Lagrangian which is required for inflationary magnetogenesis arises naturally in the Poincar{\'e} Gauge Theory. We use the minimal coupling prescription to introduce the…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-08 M. V. S. Saketh , R. Kothari , P. Jain

The magnetogenesis scenarios triggered by the early variation of the gauge coupling are critically analyzed. In the absence of sources, it is shown that the electric and magnetic power spectra can be explicitly computed by means of…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-29 Massimo Giovannini

We show that conformal invariance of gauge fields is naturally broken in inflation, having as a consequence amplification of gauge fields. The resulting spectrum of the field strength is approximately B_L ~ L^(-1), where L is the relevant…

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

We discuss the generation of primordial magnetic fields during inflation in the dilaton-axion electromagnetism, in which the dilaton and axion dynamics are introduced in terms of two time dependent functions of the cosmic scale factor,…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-18 Shu-Lin Cheng , Wolung Lee , Kin-Wang Ng

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…

High Energy Physics - Theory · Physics 2009-11-11 Mohammad A. Ganjali

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

We study the energy-momentum tensor and helicity of gauge fields coupled through $g \phi F \tilde{F}/4$ to a pseudo-scalar field $\phi$ driving inflation. Under the assumption of a constant time derivative of the background inflaton, we…

General Relativity and Quantum Cosmology · Physics 2022-01-19 M. Ballardini , M. Braglia , F. Finelli , G. Marozzi , A. A. Starobinsky

In this paper, we discuss the inflationary magnetogenesis scenario, in which the coupling function is introduced to break the conformal invariance of electromagnetic action. Unlike in conventional models, we deduce the Maxwell's equations…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Y. Li , L. Y. Zhang

The primordial density fluctuation inevitably couples to all forms of matter via loop corrections and depends on the ambient conditions while inflation was ongoing. This gives us an opportunity to observe processes which were in progress…

Astrophysics · Physics 2009-08-24 David Seery

We investigate primordial magnetogenesis by assuming the gauge field is prepared in a thermal state during inflation rather than the standard Bunch-Davies vacuum. The temperature $\mathcal{T}$ introduces a physical scale that breaks…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-12 Arjun Berera , Suddhasattwa Brahma , Zizang Qiu , Rudnei O. Ramos

We study the generation of primeval magnetic fields during inflation era in nonlinear theories of electrodynamics. Although the intensity of the produced fields strongly depends on characteristics of inflation and on the form of…

Astrophysics · Physics 2008-11-26 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

In this note we argue that the breaking of conformal invariance because of the coupling of a charged scalar field to gravity is not sufficient for the production of seed galactic magnetic fields during inflation.

High Energy Physics - Phenomenology · Physics 2009-10-31 Massimo Giovannini , Mikhail Shaposhnikov

Among primordial magnetogenesis models, inflation is a prime candidate to explain the current existence of cosmological magnetic fields. Assuming conformal invariance to be restored after inflation, their energy density decreases as…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-11 Vittoria Demozzi , Christophe Ringeval

We describe a novel proposal for inflationary magnetogenesis by identifying the non-Abelian sector of Spectator Chromo Natural Inflation (SCNI) with the $\rm{SU(2)}_{\rm L}$ sector of the Standard Model. This mechanism relies on the…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-23 Axel Brandenburg , Oksana Iarygina , Evangelos I. Sfakianakis , Ramkishor Sharma

We analyse the evolution of primordial magnetic fields in spatially flat Friedmann universes and reconsider the belief that, after inflation, these fields decay adiabatically on all scales. Without~abandoning classical electromagnetism or…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-11 Christos G. Tsagas

We consider models in which the (transverse) photon mass is non-zero during inflation and drops to zero non-adiabatically at the end of inflation. Through this process, vacuum fluctuations of the photon field are converted into physical,…

We analyse the dynamics of spinodal decomposition in inflationary cosmology using the closed time path formalism of out of equilibrium quantum field theory combined with the non-perturbative Hartree approximation. In addition to a general…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Cormier , R. Holman
‹ Prev 1 3 4 5 6 7 10 Next ›