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We perform in this work an analysis of the background dynamics for $\alpha$-attractor models in the context of loop quantum cosmology. Particular attention is given to the determination of the duration of the inflationary phase that is…

General Relativity and Quantum Cosmology · Physics 2025-06-25 G. L. L. W. Levy , Rudnei O. Ramos

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

The current epoch of accelerated cosmic expansion is postulated to be driven by dark energy, which in the standard model takes the form of a cosmological constant with equation of state parameter $w=-1$. We propose an innovative perspective…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-17 Sveva Castello , Stéphane Ilić , Martin Kunz

Recently, Kallosh and Linde have drawn attention to a new family of superconformal inflationary potentials, subsequently called $\alpha$-attractors. The $\alpha$-attractor family can interpolate between a large class of inflationary models.…

General Relativity and Quantum Cosmology · Physics 2018-10-26 Swagat S. Mishra , Varun Sahni , Yuri Shtanov

In this paper we perform a global analysis of the constraints on the inflationary parameters in the presence of dynamical dark energy models from the current observations, including the three-year Wilkinson Microwave Anisotropy Probe…

Astrophysics · Physics 2008-11-26 Jun-Qing Xia , Xinmin Zhang

We constrain spatially-flat tilted and nonflat untilted scalar field ($\phi$) dynamical dark energy inflation ($\phi$CDM) models by using Planck 2015 cosmic microwave background (CMB) anisotropy measurements and recent baryonic acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-29 Chan-Gyung Park , Bharat Ratra

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

Several attempts to solve the cosmological constant problem, which concerns the value of the cosmological constant being extremely smaller than the Standard Model mass scales, have introduced a scalar field with a very flat potential that…

High Energy Physics - Phenomenology · Physics 2024-04-10 Wen Yin

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

The DESI year one observations can help probe new physics on cosmological scales. In light of the latest DESI BAO measurements, we constrain five popular cosmological scenarios including inflation, modified gravity, annihilating dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-18 Deng Wang

We investigate the observational constraints on $\alpha$-attractor inflationary models and their post-inflationary reheating dynamics in light of the latest CMB data from ACT DR6 combined with Planck18, BICEP/$Keck$ 2018, and DESI…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-06 Md Riajul Haque , Sourav Pal , Debarun Paul

A class of inflation theories called $\alpha$-attractors has been investigated recently with interesting properties interpolating between quadratic potentials, the Starobinsky model, and an attractor limit. Here we examine their use for…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Eric V. Linder

We investigate the constraining power of future CMB and galaxy surveys on models of quintessential inflation realized within the framework of $\alpha$-attractors. We analyze how these future datasets will probe the parameter space of…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-30 G. Rodrigues , F. B. M. dos Santos , S. Santos da Costa , J. G. Rodrigues , R. von Marttens , R. Silva , D. F. Mota , J. S. Alcaniz

We construct a family of viable scalar-tensor models of dark energy (DE) which possess a phase of late-time acceleration preceded by a standard matter era, while at the same time satisfying the local gravity constraints (LGC). The coupling…

Astrophysics · Physics 2008-11-26 Shinji Tsujikawa , Kotub Uddin , Shuntaro Mizuno , Reza Tavakol , Jun'ichi Yokoyama

In a model of the late-time cosmic acceleration within the framework of generalized Proca theories, there exists a de Sitter attractor preceded by the dark energy equation of state $w_{\rm DE}=-1-s$, where $s$ is a positive constant. We run…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-05 Antonio De Felice , Lavinia Heisenberg , Shinji Tsujikawa

We study the minimally and non-minimally coupled scalar field models as possible alternatives for dark energy, the mysterious energy component that is driving the accelerated expansion of the universe. After discussing the dynamics at both…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Zahra Davari , Valerio Marra , Mohammad Malekjani

In the era of precision cosmology, the cosmological constant $\Lambda$ gives quite an accurate description of the evolution of the Universe, but it is still plagued with the fine-tuning problem and the cosmic coincidence problem. In this…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-27 Srijita Sinha , Narayan Banerjee

We present an explicit cosmological model where inflation and dark energy both could arise from the dynamics of the same scalar field. We present our discussion in the framework where the inflaton field $\phi$ attains a nearly constant…

High Energy Physics - Theory · Physics 2008-11-26 Ishwaree P. Neupane

We perform a comprehensive study of a class of dark energy models - scalar field models where the effective potential can be described by a polynomial series - exploring their dynamical behavior using the method of flow equations that has…

Astrophysics · Physics 2008-11-26 Dragan Huterer , Hiranya V. Peiris

We provide a unified description of cosmological $\alpha$-attractors and late-time acceleration, in excellent agreement with the latest Planck data. Our construction involves two superfields playing distinctive roles: one is the dynamical…

High Energy Physics - Theory · Physics 2015-12-29 Marco Scalisi