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Related papers: Universality and scaling in multi-field $\alpha$-a…

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We analyze and compare the multi-field dynamics during inflation and preheating in symmetric and asymmetric models of $\alpha$-attractors, characterized by a hyperbolic field-space manifold. We show that the generalized (asymmetric) E- and…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-04 Oksana Iarygina , Evangelos I. Sfakianakis , Dong-Gang Wang , Ana Achúcarro

We study (p)reheating in alpha-attractor T-models of inflation, taking into account both scalar fields present in these models: the inflaton and the spectator. The two-field model has a negative field-space curvature which, at the end of…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Tomasz Krajewski , Krzysztof Turzyński , Michał Wieczorek

The observational signatures of multi-field inflation will generally evolve as the Universe reheats. We introduce a general analytic formalism for tracking this evolution through perturbative reheating, applicable to two field models with…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-28 Joseph Elliston , Stefano Orani , David J. Mulryne

We explore the dynamics of multi-field models of inflation in which the field-space metric is a hyperbolic manifold of constant curvature. Such models are known as $\alpha$-attractors and their single-field regimes have been extensively…

High Energy Physics - Theory · Physics 2021-12-14 Perseas Christodoulidis , Diederik Roest , Evangelos I. Sfakianakis

This is the first of a three-part series of papers, in which we study the preheating phase for multifield models of inflation involving nonminimal couplings. In this paper, we study the single-field attractor behavior that these models…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-30 Matthew P. DeCross , David I. Kaiser , Anirudh Prabhu , Chanda Prescod-Weinstein , Evangelos I. Sfakianakis

Cosmological $\alpha$-attractors stand out as particularly compelling models to describe inflation in the very early universe, naturally meeting tight observational bounds from cosmic microwave background (CMB) experiments. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-22 Laura Iacconi , Hooshyar Assadullahi , Matteo Fasiello , David Wands

Preheating at the end of inflation is a violent nonlinear process that efficiently transfers the energy of the inflaton to a second field, the preheat field. When the preheat field is light during inflation and its background value…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 Zhiqi Huang , Xichang Ouyang , Yu Cui , Jianqi Liu , Yanhong Yao , Zehong Qiu , Guangyao Yu , Lu Huang , Zhuoyang Li , Chi-Fong Wong

The robustness of multi-field inflation to the physics of reheating is investigated. In order to carry out this study, reheating is described in detail by means of a formalism which tracks the evolution of scalar fields and perfect fluids…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Jerome Martin , Lucas Pinol

Whereas preheating after chaotic and hybrid inflation models has been abundantly studied in the literature, preheating in small field inflation models, where the curvature of the inflaton potential is negative during inflation, remains less…

High Energy Physics - Theory · Physics 2015-03-17 Philippe Brax , Jean-Francois Dufaux , Sophie Mariadassou

We explore in detail the dynamics of multi-field inflationary models. We first revisit the two-field case and rederive the coordinate independent expression for the attractor solution with either small or large turn rate, emphasizing the…

High Energy Physics - Theory · Physics 2023-11-13 Perseas Christodoulidis , Robert Rosati

Recent years have seen the introduction of various multi-field inflationary scenarios in which the curvature and geodesics of the scalar manifold play a crucial role. We outline a simple description that unifies these different proposals…

General Relativity and Quantum Cosmology · Physics 2020-08-14 Perseas Christodoulidis , Diederik Roest , Evangelos I. Sfakianakis

Preheating following the inflationary phase in models of open inflation is considered. The most significant difference from a preheating scenario in flat space is that supercurvature modes can be populated and amplified in the open…

Astrophysics · Physics 2007-05-23 David I. Kaiser

In this note I study preheating after multi-field inflation to assess the feasibility of parametric resonance. An intuitive argument for the suppression of resonances due to dephasing of fields in generic multi-field models is presented.…

Astrophysics · Physics 2009-10-02 Diana Battefeld

We study in detail (p)reheating after multi-field inflation models with a particular focus on N-flation. We consider a variety of different couplings between the inflatons and the matter sector, including both quartic and trilinear…

High Energy Physics - Theory · Physics 2015-03-17 Neil Barnaby , Jonathan Braden , Lev Kofman

We investigate a compelling model of quintessential inflation in the context of $\alpha$-attractors, which naturally result in a scalar potential featuring two flat regions, the inflationary plateau and the quintessential tail. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Konstantinos Dimopoulos , Leonora Donaldson Wood , Charlotte Owen

In single field inflationary models, preheating refers to the phase that immediately follows inflation, but precedes the epoch of reheating. During this phase, the inflaton typically oscillates at the bottom of its potential and gradually…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-25 Dhiraj Kumar Hazra , Jerome Martin , L. Sriramkumar

We study multifield contributions to the scalar power spectrum in an ensemble of six-field inflationary models obtained in string theory. We identify examples in which inflation occurs by chance, near an approximate inflection point, and we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Liam McAllister , Sébastien Renaux-Petel , Gang Xu

We study $\alpha$-attractor models with both E-model and T-model potential in an extended Non-Minimal Derivative (NMD) inflation where a canonical scalar field and its derivatives are non-minimally coupled to gravity. We calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-19 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

Models of cosmic inflation suggest that our universe underwent an early phase of accelerated expansion, driven by the dynamics of one or more scalar fields. Inflationary models make specific, quantitative predictions for several observable…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-10 David I. Kaiser

We study the impact of perturbative reheating on primordial observables in models of multiple-field inflation. By performing a sudden decay calculation, we derive analytic expressions for the local-type non-linearity parameter $f_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-14 Joel Meyers , Ewan R. M. Tarrant
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