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Related papers: Reheating after Axion Inflation

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We revisit the gravitational leptogenesis scenario in which the inflaton is coupled to gravity by the Chern-Simons term and the lepton asymmetry is generated through the gravitational anomaly in the lepton number current during inflation.…

High Energy Physics - Phenomenology · Physics 2020-02-05 Kohei Kamada , Jun'ya Kume , Yusuke Yamada , Jun'ichi Yokoyama

The generation of helical magnetic fields and the associated chiral asymmetry via the chiral anomaly is a generic feature in pseudoscalar inflation. In the presence of a Chern--Simons coupling between the inflaton and a U(1) gauge field,…

High Energy Physics - Phenomenology · Physics 2025-12-25 Di Wu , Yifan Hu , Kohei Kamada

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 study SU($N$) gauge fields that couple to the inflaton through the Chern-Simons term. We provide a general procedure to construct homogeneous, isotropic, and attractor solutions of the gauge fields during inflation. The gauge fields…

High Energy Physics - Phenomenology · Physics 2022-05-20 Tomohiro Fujita , Kyohei Mukaida , Kai Murai , Hiromasa Nakatsuka

We study preheating in a general class of supersymmetric hybrid inflation model. Supersymmetry leads to only one coupling constant in the potential and thus only one natural frequency of oscillation for the homogeneous fields, whose…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Bastero-Gil , S. F. King , J. Sanderson

A direct coupling between the inflaton and Standard Model gluons can dynamically raise the QCD confinement scale during inflation, making the axion temporarily heavy and suppressing axion isocurvature perturbations. As inflation proceeds,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-21 Katherine Freese , Evangelos I. Sfakianakis , Barmak Shams Es Haghi

Pseudo-scalar inflation coupled with U(1) gauge fields through the Chern-Simons term has been extensively studied. However, new physics arising from UV theories may still influence the pseudo-scalar field at low-energy scales, potentially…

High Energy Physics - Theory · Physics 2024-02-06 Chong-Bin Chen , Ziwei Wang , Siyi Zhou

Inflaton couplings during warm inflation result in the production of a thermal bath. Thermal friction and fluctuations can dominate the standard de Sitter analogues, resulting in a modified slow-roll scenario with a new source of density…

High Energy Physics - Phenomenology · Physics 2026-05-22 Edward Broadberry , Anson Hook , Sagnik Mondal

Processes of particle production during inflation can increase the amplitude of the scalar metric perturbations. We show that such a mechanism can naturally arise in supergravity models where an axion-like field, whose potential is…

High Energy Physics - Phenomenology · Physics 2021-07-07 Michael A. Roberts , Lorenzo Sorbo

We present the general discussion on the inflection point inflation with small or large inflaton fields and show the effects of reheating dynamics on the inflationary predictions. In order to compare the model predictions with precisely…

High Energy Physics - Phenomenology · Physics 2016-07-20 Hyun Min Lee

Here we consider the possibility of preheating the Universe via the parametric amplification of a massless, U(1) abelian gauge field. We assume that the gauge field is coupled to the inflaton via a conformal factor with one free parameter.…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-02 J. Tate Deskins , John T. Giblin , Robert R. Caldwell

We study reheating processes and its cosmological consequences in the Starobinsky model embedded in the old-minimal supergravity. First, we consider minimal coupling between the gravity and matter sectors in the higher curvature theory, and…

High Energy Physics - Phenomenology · Physics 2015-06-23 Takahiro Terada , Yuki Watanabe , Yusuke Yamada , Jun'ichi Yokoyama

Sphaleron heating has been recently proposed as a mechanism to realize warm inflation when inflaton is an axion coupled to pure Yang-Mills. As a result of heating, there is a friction coefficient $\gamma \propto T^3$ in the equation of…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-28 Mehrdad Mirbabayi , Andrei Gruzinov

We study the dynamics of $SU(2)_L$ times $U(1)_Y$ electroweak gauge fields during and after Higgs inflation. In particular, we investigate configurations of the gauge fields during inflation and find the gauge fields remain topologically…

High Energy Physics - Theory · Physics 2014-08-06 Ippei Obata , Takashi Miura , Jiro Soda

We present a toy model of an axion gauge field inflation scenario that yields viable density and gravitational wave spectra. The scenario consists of an axionic inflaton in a steep potential that is effectively flattened by a coupling to a…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-12 R. R. Caldwell , C. Devulder

We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains $\phi^4$ term as well as terms in the original hybrid inflation model. In our model, inflation…

High Energy Physics - Theory · Physics 2011-02-22 Seoktae Koh , Masato Minamitsuji

We consider inflation driven by an axion-like particle coupled to an SU(2) gauge sector via a Chern-Simons term. Known as chromo-natural inflation, this scenario is in tension with CMB observations. In order to remedy this fact and preserve…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-21 Ema Dimastrogiovanni , Matteo Fasiello , Martino Michelotti , Lucas Pinol

We study perturbative reheating at the end of fibre inflation where the inflaton is a closed string modulus with a Starobinsky-like potential. We first derive the spectral index $n_s$ and the tensor-to-scalar ratio $r$ as a function of the…

High Energy Physics - Theory · Physics 2019-03-26 Michele Cicoli , Gabriel A. Piovano

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 study the multifield dynamics of axion models nonminimally coupled to gravity. As usual, we consider a canonical $U(1)$ symmetry-breaking model in which the axion is the phase of a complex scalar field. If the complex scalar field has a…

High Energy Physics - Theory · Physics 2024-06-07 Evan McDonough , Alan H. Guth , David I. Kaiser