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Related papers: Closing in on $\alpha$-attractors

200 papers

We investigate the observational viability of a class of $\alpha$-attractors inflationary models in light of the most recent Cosmic Microwave Background (CMB) and Large-Scale Structure (LSS) data. By considering a double-well potential we…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-04 J. G. Rodrigues , S. Santos da Costa , J. S. Alcaniz

The $\alpha$-attractor inflationary models are nowadays favored by CMB Planck observations. Their similarity with canonical quintessence models motivates the exploration of a common framework that explains both inflation and dark energy. We…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-18 Carlos García-García , Pilar Ruíz-Lapuente , David Alonso , M. Zumalacárregui

We study inflationary constraints from reheating on two classes of single-field inflationary models: a generalized $\alpha$-attractor with potential $V(\phi) = V_0 \!\left(1 - \sech^p\!\left[\phi/(\sqrt{6\alpha}\,M_{Pl})\right]\right)$ and…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Gabriel German , Juan Carlos Hidalgo

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

A systematic approach is presented for using CMB observables and reheating temperature for discriminating between various models of inflation and certain freeze-in dark matter scenarios. It is applied to several classes of…

High Energy Physics - Phenomenology · Physics 2025-11-26 Anish Ghoshal , Paweł Kozów , Marek Olechowski , Stefan Pokorski

The $\alpha$-attractor models of inflation have remained one of the preferred inflationary models for nearly a decade now. The unique attractor nature of these models in the $n_s-r$ plane have put these models in the sweet-spot of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-04 Dibya Chakraborty , Suratna Das

Single-field models of $\alpha$-attractor quintessential inflation provide a unified picture of the two periods of early- and late-time cosmic acceleration, where both inflation and dark energy are described by a single scalar degree of…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-05 Yashar Akrami , Santiago Casas , Senwen Deng , Valeri Vardanyan

We propose a scenario where preheating occurs for a specific duration that is parametrized by an e-folds number $N_{pre}$, our results suggest a direct correlation between the preheating duration and the density of gravitational waves (GWs)…

General Relativity and Quantum Cosmology · Physics 2022-09-21 K. El Bourakadi , Z. Sakhi , M. Bennai

We derive the reconstruction formulae for the inflation model with the non-minimal derivative coupling term. If reconstructing the potential from the tensor-to-scalar ratio, we could obtain the potential without using the high friction…

General Relativity and Quantum Cosmology · Physics 2020-11-23 Qin Fei , Zhu Yi , Yingjie Yang

Production of gravitationally coupled light moduli fields must be suppressed in the early universe, so that its decay products do not alter Big Bang Nucleosynthesis (BBN) predictions for light elements. On the other hand, the moduli quanta…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-01 Khursid Alam , Mar Bastero-Gil , Koushik Dutta , H. V. Ragavendra

Evidence from the BICEP2 experiment for a significant gravitational-wave background has focussed attention on inflaton potentials $V(\phi) \propto \phi^\alpha$ with $\alpha=2$ ("chaotic" or "$m^2\phi^2$" inflation) or with smaller values of…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-30 Liang Dai , Marc Kamionkowski , Junpu Wang

We study reheating in $\alpha$-attractor models of inflation in which the inflaton couples to other scalars or fermions. We show that the parameter space contains viable regions in which the inflaton couplings to radiation can be determined…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-22 Marco Drewes , Jin U Kang , Ui Ri Mun

We study here the observational constraints on single-field inflationary models achievable with the next generation of CMB experiments. We particularly focus on a Stage-IV like experiment and forecasts its constraints on inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-01 Guadalupe Cañas-Herrera , Fabrizio Renzi

We carry out a fully analytical study of the phenomenology of $\alpha$-attractor T-models defined by the potential $V = V_0\tanh^ p\left(\lambda \phi/M_{pl}\right)$. We obtain expressions for the number of e-folds during inflation $N_{ke}$…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-22 Gabriel German

Recent BICEP/Keck data on the cosmic microwave background, in combination with previous WMAP and Planck data, impose strong new constraints on the tilt in the scalar perturbation spectrum, $n_s$, as well as the tensor-to-scalar ratio, $r$.…

High Energy Physics - Phenomenology · Physics 2022-02-16 John Ellis , Marcos A. G. Garcia , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner

After the inflationary phase, the universe enters the preheating phase, during which the inflaton field rolls down its potential and oscillates. When the potential significantly deviates from a parabolic shape at its minimum, these…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-21 Daniel del-Corral , Paolo Gondolo , K. Sravan Kumar , João Marto

Recent observations from the Atacama Cosmology Telescope (ACT) indicate a moderate upward shift in the scalar spectral index $n_s$ compared to Planck $2018$, thereby placing tighter constraints on inflationary scenarios. Motivated by these…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-25 Li-Yang Chen , Rongrong Zha , Feng-Yi Zhang

Reheating is the the epoch which connects inflation to the subsequent hot Big-Bang phase. Conceptually very important, this era is however observationally poorly known. We show that the current Planck satellite measurements of the Cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-08 Jerome Martin , Christophe Ringeval , Vincent Vennin

The most recent data release from the Atacama Cosmology Telescope (ACT) reveals a larger value of the scalar spectral tilt $n_s$, ruling out a broad class of inflationary attractors. In this paper, we consider inflationary models including…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Qing Gao , Yanjiang Qian , Yungui Gong , Zhu Yi

We present a comprehensive study of warm hybrid inflation within the framework of $\alpha$-attractor models, where an axionic inflaton is coupled to a waterfall field in the presence of thermal dissipation. The model is analyzed for both…

High Energy Physics - Phenomenology · Physics 2026-01-16 Waqas Ahmed , Waqar Ahmad , Ahsan Illahi , M. Junaid