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

200 papers

We study the role of $\alpha$-parameter of the newly proposed model of quintessential $\alpha$-attractor inflation (arXiv: 2305.00230 [gr-qc]) to the case of quintessential spontaneous baryogenesis and generation of relic gravitational…

High Energy Physics - Theory · Physics 2024-03-28 Arunoday Sarkar , Buddhadeb Ghosh

Recent results from the Atacama Cosmology Telescope (ACT), when combined with Planck and DESI datasets, indicate a scalar spectral index $n_s$ larger than that reported in the Planck 2018 baseline, thereby challenging conventional…

High Energy Physics - Phenomenology · Physics 2025-12-02 Shuntaro Aoki , Hajime Otsuka , Ryota Yanagita

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

[Abridged] A variety of model-dependent as well as model-independent approaches suggest that certain localized features in the primordial scalar power spectrum can lead to a significantly better fit to the observed anisotropies in the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-16 Alipriyo Hoory , Dhiraj Kumar Hazra , L. Sriramkumar

Traditionally, inflationary models are analyzed in terms of parameters such as the scalar spectral index ns and the tensor to scalar ratio r, while dark energy models are studied in terms of the equation of state parameter w. Motivated by…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Stéphane Ilic , Martin Kunz , Andrew R. Liddle , Joshua A. Frieman

We develop a potential-independent cosmographic framework, in which cosmographic parameters are promoted to dynamical variables within a closed autonomous system. Although the cosmographic hierarchy is formally infinite, we achieve closure…

General Relativity and Quantum Cosmology · Physics 2026-05-13 Seturumane Tema , S. Shajidul Haque , Saurya Das , Peter Dunsby

We present the power spectra of the scalar- and tensor-type structures generated in an inflation model based on the nonminimally coupled scalar field with a self coupling. By comparing the contributions of these structures to the anisotropy…

Astrophysics · Physics 2013-07-09 H. Noh , J. Hwang

We investigate anisotropic inflation within the single-field model featuring an intermediate scale factor. Our analysis reveals that the anisotropic nature of the Friedmann equations in this framework affects the slow-roll parameters, which…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 Maryam Roushan , Narges Rashidi , Kourosh Nozari

We study the large scale power spectrum of gravitational wave perturbations of the microwave background in the context of single-bubble open inflation models. We compute the ratio of tensor to scalar contributions to the CMB anisotropies as…

Astrophysics · Physics 2016-08-25 Juan Garcia-Bellido

We construct a toy a model which demonstrates that large field single scalar inflation can produce an arbitrarily small scalar to tensor ratio in the window of e-foldings recoverable from CMB experiments. This is done by generalizing the…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-13 Daniel J. Brooker

Here, a single field inflationary model driven by a mutated hilltop potential, a subclass of the hilltop models of inflation, is investigated. To constrain the parameter space, we employ the latest $r-n_{\rm s}$ constraints from Planck…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-11 Iraj Safaei , Soma Heydari , Milad Solbi , Kayoomars Karami

We have recently proposed attractor models for modulus fixing, inflation, supersymmetry breaking and dark energy based on no-scale supergravity. In this paper we develop phenomenological and cosmological aspects of these no-scale attractor…

High Energy Physics - Phenomenology · Physics 2020-09-02 John Ellis , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner

The Higgs inflation model with nonminimal coupling, while disfavored by the 1$\sigma$ region of the latest Atacama Cosmology Telescope Data Release 6 (ACT DR6) observational data, can be reconciled with the ACT DR6 data by incorporating the…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-01 Lang Liu , Zhu Yi , Yungui Gong

This paper revisits the Inflationary scenario within the framework of scalar field models possessing a non-canonical kinetic term. We obtain closed form solutions for all essential quantities associated with chaotic inflation including slow…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-03 Sanil Unnikrishnan , Varun Sahni , Aleksey Toporensky

We show that if the $\alpha$-attractor model is realized by the spontaneous breaking of the scale symmetry, then the stability and the dynamics of the vector field that gauges the scale symmetry can severely constrain the $\alpha$-parameter…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Ozgur Akarsu , Sibel Boran , Emre O. Kahya , Nese Ozdemir , Mehmet Ozkan

Successful inflationary models should (i) describe the data well; (ii) arise generically from sensible UV completions; (iii) be insensitive to detailed fine-tunings of parameters and (iv) make interesting new predictions. We argue that a…

High Energy Physics - Theory · Physics 2016-08-30 C. P. Burgess , M. Cicoli , S. de Alwis , F. Quevedo

Recent results from the Atacama Cosmology Telescope (ACT) indicate a scalar spectral index $n_s \simeq 0.9743$, in excellent agreement with the prediction of linear inflation. However, the corresponding tensor-to-scalar ratio $r \simeq…

General Relativity and Quantum Cosmology · Physics 2025-04-18 Christian Dioguardi , Alexandros Karam

Understanding the properties of dark matter has proved to be one of the most challenging problems of particle phenomenology. In this paper, we have tried to understand the phenomenology of dark matter in light of very well understood…

High Energy Physics - Phenomenology · Physics 2018-11-28 Debaprasad Maity , Pankaj Saha

We consider a cosmological model in which the tensor mode becomes massive during inflation, and study the Cosmic Microwave Background (CMB) temperature and polarization bispectra arising from the mixing between the scalar mode and the…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-24 Guillem Domènech , Takashi Hiramatsu , Chunshan Lin , Misao Sasaki , Maresuke Shiraishi , Yi Wang

A new family of inflation models is introduced and studied. The models are characterised by a scalar potential which, far from the origin, approaches an inflationary plateau in a power-law manner, while near the origin becomes monomial, as…

High Energy Physics - Phenomenology · Physics 2015-11-20 Konstantinos Dimopoulos