English
Related papers

Related papers: $\alpha$-attractor potentials in loop quantum cosm…

200 papers

In recent years, the detection of gravitational waves by LIGO and PTA collaborations have raised the intriguing possibility of excess matter power at small scales. Such an increase can be achieved by ultra slow roll (USR) phase during…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 H. V. Ragavendra , Anjan Kumar Sarkar , Shiv K. Sethi

Extending the work of Ferrara and one of the authors, we present dynamical cosmological models of $\alpha$-attractors with plateau potentials for $3\alpha=1,2,3,4,5,6,7$. These models are motivated by geometric properties of maximally…

High Energy Physics - Theory · Physics 2017-05-22 Renata Kallosh , Andrei Linde , Timm Wrase , Yusuke Yamada

The coupling between spin and torsion in the Einstein-Cartan-Sciama-Kibble theory of gravity generates gravitational repulsion at very high densities, which prevents a singularity in a black hole and may create there a new universe. We show…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-22 Shantanu Desai , Nikodem J. Poplawski

We investigate a compelling model of quintessential inflation in the context of $\alpha$-attractors, which naturally result in a scalar potential featuring two flat regions, the inflationary plateau and the quintessential tail. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Konstantinos Dimopoulos , Leonora Donaldson Wood , Charlotte Owen

In this paper, we apply reconstruction techniques to recover the potential parameters for a particular class of single-field models, the $\alpha$-attractor (supergravity) models of inflation. This also allows to derive the inflaton vacuum…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-28 A. Di Marco , P. Cabella , N. Vittorio

In this article, I mainly discuss the dynamics of the pre-inflationary Universe for the potential $V(\phi) \propto \phi^n$ with $n=5/3$ in the context of loop quantum cosmology, in which the big bang singularity is resolved by a…

General Relativity and Quantum Cosmology · Physics 2018-08-14 M. Shahalam

We provide an exhaustive numerical exploration of the predictions of loop quantum cosmology (LQC) with a post-bounce phase of inflation for the primordial power spectrum of scalar and tensor perturbations. We extend previous analysis by…

General Relativity and Quantum Cosmology · Physics 2015-12-30 Ivan Agullo , Noah A. Morris

We study the role of the Barbero-Immirzi parameter $\gamma$ and the choice of connection in the construction of (a symmetry-reduced version of) loop quantum gravity. We start with the four-dimensional Lorentzian Holst action that we reduce…

General Relativity and Quantum Cosmology · Physics 2015-05-19 Jibril Ben Achour , Marc Geiller , Karim Noui , Chao Yu

In this paper we constrain some aspects of the general postinflationary phase in the context of superconformal $\alpha$-attractor models of inflation. In particular, we provide constraints on the duration of the reheating process,…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Alessandro Di Marco , Paolo Cabella , Nicola Vittorio

We investigate a particle physics model for cosmic inflation based on the following assumptions: (i) there are at least two complex scalar fields; (ii) the scalar potential is bounded from below and remains perturbative up to the Planck…

High Energy Physics - Phenomenology · Physics 2020-04-01 Zoltán Péli , István Nándori , Zoltán Trócsányi

Quintessential inflation models provide a framework that simultaneously describes inflation and dynamical dark energy, the latter of which has recently received growing support from DESI observations. A distinctive feature of these models…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-04 Changcheng Jing , George Alestas , Sachiko Kuroyanagi

We present a new approach to constructing inflationary models in closed universes. Conformal embedding of closed-universe models in a de Sitter background suggests a quantisation condition on the available conformal time. This condition…

Astrophysics · Physics 2009-11-10 Anthony Lasenby , Chris Doran

In this work we shall study the implications of a subclass of $E$-models cosmological attractors, namely of $a$-attractors, on hydrodynamically stable slowly rotating neutron stars. Specifically, we shall present the Jordan frame theory of…

General Relativity and Quantum Cosmology · Physics 2021-03-16 S. D. Odintsov , V. K. Oikonomou

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

Within the $\alpha$-attractors framework we investigate scalar potentials with the same pole as the one featured in the kinetic term. We show that, in field space, this leads to directions without a plateau. Using this, we present a…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Konstantinos Dimopoulos , Michal Artymowski

In the large extra dimensional braneworld inflation, Friedmann equation is modified to include a quadratic term in energy density with an additional parameter $\lambda$ called brane tension in addition to the usual linear term. The high…

General Relativity and Quantum Cosmology · Physics 2020-01-15 Mudassar Sabir , Waqas Ahmed , Yungui Gong , Yizhou Lu

In this paper we consider the $\alpha-$attractor model and study inflation under a non-slow-roll dynamics. More precisely, we follow the approach recently proposed by Gong and Sasaki \cite{Gong:2015ypa} by means of assuming…

General Relativity and Quantum Cosmology · Physics 2016-04-05 K. Sravan Kumar , João Marto , Paulo Vargas Moniz , Suratna Das

The full set of cosmological observables coming from linear scalar and tensor perturbations of loop quantum cosmology is computed in the presence of inverse-volume corrections. Background inflationary solutions are found at linear order in…

General Relativity and Quantum Cosmology · Physics 2011-03-28 Martin Bojowald , Gianluca Calcagni

Motivated by $\alpha$-attractor models, in this paper we consider a Gauss-Bonnet inflation with E-model type of potential. We consider the Gauss-Bonnet coupling function to be the same as the E-model potential. In the small $\alpha$ limit…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 Kourosh Nozari , Narges Rashidi

In this study, we explore the pre-inflationary dynamics of the universe using a noncommutative extension of the mLQC-I framework. By incorporating a scalar field potential, we show that key features of Loop Quantum Cosmology (LQC), such as…

General Relativity and Quantum Cosmology · Physics 2024-08-13 Abolhassan Mohammadi
‹ Prev 1 3 4 5 6 7 10 Next ›