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Related papers: Dark Energy from $\alpha$-Attractors

200 papers

The Dark Side of the Universe, which includes the cosmological inflation in the early Universe, the current dark energy and dark matter, can be theoretically described by supergravity, though it is non-trivial. We recall the arguments pro…

High Energy Physics - Theory · Physics 2019-09-18 Sergei V. Ketov

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

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 investigate a constraint on reheating followed by alpha-attractor-type inflation (the E-model and T-model) from an observation of the spectral index n_s. When the energy density of the universe is dominated by an energy component with…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-04 Yoshiki Ueno , Kazuhiro Yamamoto

I show that the problem of realizing inflation in theories with random potentials of a limited number of fields can be solved, and agreement with the observational data can be naturally achieved if at least one of these fields has a…

High Energy Physics - Theory · Physics 2017-02-22 Andrei Linde

Rubano and Barrow have discussed the emergence of a dark energy, with late-time cosmic acceleration arising from a self-interacting homogeneous scalar field with a potential of hyperbolic power type. Here, we study the evolution of this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Spyros Basilakos , John D. Barrow

The present epoch of accelerated cosmic expansion is supposed to be driven by an unknown constituent called dark energy, which in the standard model takes the form of a cosmological constant, characterized by a constant equation of state…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-30 Sveva Castello , Stéphane Ilić , Martin Kunz

We show that current cosmic acceleration can be explained by an almost massless scalar field experiencing quantum fluctuations during primordial inflation. Provided its mass does not exceed the Hubble parameter today, this field has been…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-08 Christophe Ringeval , Teruaki Suyama , Tomo Takahashi , Masahide Yamaguchi , Shuichiro Yokoyama

We present a mechanism for the emergence of cosmic acceleration within the mean-field approximation of Group Field Theory models of quantum gravity. Depending on the interaction type, the resulting cosmological dynamics can either feature a…

General Relativity and Quantum Cosmology · Physics 2025-12-15 Luca Marchetti , Tom R. Ladstätter , Daniele Oriti

We propose a unified model of dark energy and inflation through the Markov-Mukhanov modification of the Einstein-Hilbert action, where the matter sector is coupled to gravity via a scalar coupling function depending only on the energy…

General Relativity and Quantum Cosmology · Physics 2025-12-18 Hrishikesh Chakrabarty , Daniele Malafarina

A generic outcome of theories with scalar-tensor coupling is the existence of inflationary attractors, either power-law or de Sitter. The fluctuations arising during this phase are Gaussian and their spectrum depends on the wavenumber $k$…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Luca Amendola , Diego Bellisai , Franco Occhionero , Rome Astronomical Observatory

In order to solve the fine-tuning problem of the cosmological constant, we propose a simple model with the vacuum energy non-minimally coupled to the inflaton field. In this model, the vacuum energy decays to the inflaton during…

General Relativity and Quantum Cosmology · Physics 2016-06-27 Chao-Qiang Geng , Chung-Chi Lee

In models of coupled dark energy, in which a dark energy scalar field couples to other matter components, it is natural to expect a coupling to the inflaton as well. We explore the consequences of such a coupling in the context of single…

General Relativity and Quantum Cosmology · Physics 2009-10-29 Philippe Brax , Carsten van de Bruck , Lisa M. H. Hall , Joel M. Weller

It is usually assumed that during the reheating period of inflation the inflaton field behaves coherently and follows a classical path. It is pointed out that a background inflaton field \phi_0 falling down a potential density V(\phi) can…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-16 Max Chaves

We propose a scenario that can explain the early-time inflation and the late-time dark energy within a unified framework. A scalar potential combining power-law and exponential type in a context of extended Jordan-Brans-Dicke gravity is…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-15 Kunio Kaneta , Kin-ya Oda , Motohiko Yoshimura

In the warm inflation scenario, the early cosmic acceleration is driven by the inflaton coupled to thermal fields, decaying into radiation and leaving a hot universe populated by relativistic particles after the end of inflation. The…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-25 F. B. M. dos Santos , R. de Souza , J. S. Alcaniz

The increasing interest in studying the role of holographic dark energy in the evolution of the very early universe motivates us to study it for the scenario of warm inflation. Due to this scenario, the holographic dark energy, which now…

General Relativity and Quantum Cosmology · Physics 2022-01-05 Abolhassan Mohammadi

We offer a geometric interpretation of attractor theories with singular kinetic terms as a union of multiple canonical models. We demonstrate that different domains (separated by poles) can drastically differ in their phenomenology. We…

High Energy Physics - Theory · Physics 2019-09-25 Sotirios Karamitsos

We study post-inflationary evolution in $\alpha$-attractor T-models of inflation. We consider the dynamics of both scalar fields present in these models: the inflaton and the spectator, as a negative field-space curvature may lead to…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Tomasz Krajewski , Krzysztof Turzyński

We consider two non-canonical scalar fields (tachyon and DBI) with E-model type of the potential. We study cosmological inflation in these models to find possible $\alpha$-attractors. We show that similar to the canonical scalar field case,…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Narges Rashidi , Kourosh Nozari
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