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Cosmological alpha-attractors give a natural explanation for the spectral index n_s of inflation as measured by Planck while predicting a range for the tensor-to-scalar ratio r, consistent with all observations, to be measured more…

High Energy Physics - Theory · Physics 2015-09-02 John Joseph M. Carrasco , Renata Kallosh , Andrei Linde , Diederik Roest

We identify the effective theory describing inflationary super-Hubble scales and show it to be a special case of effective field theories appropriate to open systems. Open systems allow information to be exchanged between the degrees of…

High Energy Physics - Theory · Physics 2015-09-01 C. P. Burgess , R. Holman , G. Tasinato , M. Williams

Cosmological $\alpha$-attractors are a compelling class of inflationary models. They lead to universal predictions for large-scale observables, broadly independent from the functional form of the inflaton potential. In this work we derive…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-21 Laura Iacconi , Matteo Fasiello , Jussi Väliviita , David Wands

Kination dominated quintessence models of dark energy have the intriguing feature that the relic abundance of thermal cold dark matter can be significantly enhanced compared to the predictions from standard cosmology. Previous treatments of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Daniel J. H. Chung , Lisa L. Everett , Konstantin T. Matchev

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

The study of reheating in inflationary models is crucial for understanding the early universe and gaining insights into inflationary dynamics and parameters. The reheating temperature $T_{re}$ and the duration of the reheating phase,…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-02 Gabriel German , Juan Carlos Hidalgo , Luis E. Padilla

Decoupling of heavy modes in effective low energy theory is one of the most fundamental concepts in physics. It tells us that modes must have a negligible effect on the physics of gravitational backgrounds with curvature radius larger than…

High Energy Physics - Theory · Physics 2020-05-12 Gia Dvali , Alex Kehagias , Antonio Riotto

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

The observational constraints on the primordial power spectrum have tightened considerably with the release of the first year analysis of the WMAP observations, especially when combined with the results from other CMB experiments and galaxy…

High Energy Physics - Phenomenology · Physics 2009-11-10 Dominik J. Schwarz , Cesar A. Terrero-Escalante

An exponential kind of quintessential inflation potential motivated by supergravity is studied. This type belongs to the class of {\alpha}-attractor models. The model was studied for the first time by Dimopoulos and Owen in [J. Cosmol.…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-01 Llibert Aresté Saló , David Benisty , Eduardo I. Guendelman , Jaume de Haro

For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Cormier

In this paper we will analyze generic predictions of an inflection-point model of inflation with Hubble-induced corrections and study them in light of the Planck data. Typically inflection-point models of inflation can be embedded within…

High Energy Physics - Phenomenology · Physics 2013-07-29 Sayantan Choudhury , Anupam Mazumdar , Supratik Pal

We present a new approach to quintessential inflation, in which both dark energy and inflation are explained by the evolution of a single scalar field. We start from a simple scalar potential with both oscillatory and exponential behavior.…

Astrophysics · Physics 2009-11-10 Gabriela Barenboim , Joseph Lykken

We perform a precision investigation of smooth quintessential inflation in which a single canonical scalar field unifies the two known phases of cosmic acceleration. Using a CMB-normalized runaway exponential potential, we obtain sharply…

General Relativity and Quantum Cosmology · Physics 2025-11-26 Sayantan Choudhury , Swapnil Kumar Singh , Satish Kumar Sahoo

We construct a model of quintessential inflation in Palatini $R^2$ gravity employing a scalar field with a simple exponential potential and coupled to gravity with a running non-minimal coupling. At early times, the field acts as the…

General Relativity and Quantum Cosmology · Physics 2022-11-03 Konstantinos Dimopoulos , Alexandros Karam , Samuel Sánchez López , Eemeli Tomberg

Cosmic Microwave Background (CMB) is an important probe for understanding the inflationary era of the Universe. We consider the Perturbed Power Law (PPL) model of inflation which is a soft deviation from Power Law (PL) inflationary model.…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-03 Suvodip Mukherjee , Santanu Das , Minu Joy , Tarun Souradeep

In this work, we solved the scalar and tensor perturbation equations numerically and using the improved uniform approximation method together with the third-order phase-integral method, for the $\alpha$-attractor inflationary model. This…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Jordan Zambrano , Miguel Agama , Marcos Garzón , Werner Bramer-Escamilla , Clara Rojas , Teófilo Vargas

The Starobinsky model predicts a primordial inflation period without the presence of an inflaton field. The modified version of this model predicts a simple time dependence for the Hubble parameter $H(t)$, which decreases slowly between the…

Astrophysics · Physics 2015-06-24 Reuven Opher , Ana Pelinson

We show that a combination of the simplest $\alpha$-attractors and KKLTI models related to Dp-brane inflation covers most of the area in the ($n_{s}$, $r$) space favored by Planck 2018. For $\alpha$-attractor models, there are discrete…

High Energy Physics - Theory · Physics 2021-10-26 Renata Kallosh , Andrei Linde

The $\alpha$-attractor models are some of the most interesting models of inflation from the point of view of upcoming observations in cosmology and also attractive from the point of view of supergravity. We confront representative models of…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-02 Sukannya Bhattacharya , Koushik Dutta , Mayukh R. Gangopadhyay , Anshuman Maharana