English
Related papers

Related papers: Viable Inflationary Evolution from Loop Quantum Co…

200 papers

In this paper we construct a dissipative quintessential cosmic inflation. For this purpose, we add a multiplicative dissipative term in the standard quintessence field Lagrangian. We consider the specific form of dissipation as the time…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-26 Kourosh Nozari , Fateme Rajabi , Narges Rashidi

We investigate the dynamics of super-inflation in two versions of Loop Quantum Cosmology, one in which the Friedmann equation is modified by the presence of inverse volume corrections, and one in which quadratic corrections are important.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. J. Copeland , D. J. Mulryne , N. J. Nunes , M. Shaeri

Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…

High Energy Physics - Theory · Physics 2008-11-26 Lev Kofman , Shinji Mukohyama

We use a mathematical approach based on the constraints systems in order to reconstruct the equation of state and the inflationary potential for the inflaton field from the observed spectral indices for the density perturbations $n_{s}$ and…

General Relativity and Quantum Cosmology · Physics 2018-06-12 John D. Barrow , Andronikos Paliathanasis

Slow roll reconstruction is derived from the Hamilton-Jacobi formulation of inflationary dynamics. It automatically includes information from sub-leading terms in slow roll, and facilitatesthe inclusion of priors based on the duration on…

Astrophysics · Physics 2009-06-23 Peter Adshead , Richard Easther

We consider the effective evolution of a phenomenological model from FLRW supersymmetric quantum cosmology with a scalar field. The scalar field acts as a clock and inflaton. We examine a family of simple superpotentials that produce an…

General Relativity and Quantum Cosmology · Physics 2022-08-17 N. E. Martínez-Pérez , C. Ramírez , V. M. Vázquez Báez

The fundamental difficulty in constructing a viable classical bouncing model is to evade the no-go theorem that states that, simultaneously maintaining the observational bounds on the tensor-to-scalar ratio and the non-Gaussian scalar…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-26 Debottam Nandi , Manjeet Kaur

Cosmic inflation may exhibit stochastic periods during which quantum fluctuations dominate over the semi-classical evolution. Extracting observables in these regimes is a notoriously difficult program as quantum randomness makes them fully…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-27 Baptiste Blachier , Christophe Ringeval

We eliminate the parameters originally present in models of inflation of the $\alpha$-attractor type in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. We then write expressions for the number of $e$-folds…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-02 Gabriel German

We develop a quantum-cosmological framework in which the inflationary potential emerges from the structure of the wave function of the universe rather than being postulated. Starting from the Wheeler-DeWitt equation for a flat…

General Relativity and Quantum Cosmology · Physics 2025-10-07 Gerasimos Kouniatalis

We investigate the inflationary universe in a theory where two scalar fields non-minimally coupling to the scalar curvature and an extra $R^2$ term exist and the conformal invariance is broken. In particular, the slow-roll inflation is…

High Energy Physics - Theory · Physics 2016-03-01 Kazuharu Bamba

We update the constraints on the power spectra of primordial curvature perturbation and tensor perturbation including Planck data 2015 (P15) and recently released BICEP2/Keck data (BK15), Baryon Acoustic Oscillation data and the Type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Jun Li , Qing-Guo Huang

We propose an Einstein-{\ae}ther scalar-tensor cosmological model. In particular in the scalar-tensor Action Integral we introduce the {\ae}ther field with {\ae}ther coefficients to be functions of the scalar field. This cosmological model…

General Relativity and Quantum Cosmology · Physics 2021-07-28 Andronikos Paliathanasis , Genly Leon

We show that embedding Natural Inflation in a more general scalar-tensor theory, with non-minimal couplings to the Ricci scalar and the kinetic term, alleviates the current tension of Natural Inflation with observational data. The coupling…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Guillem Simeon

The value of the tensor-to-scalar ratio $r$ in the region allowed by the latest $Planck$ 2015 measurements can be associated to a large variety of inflationary models. We discuss here the potential of future Cosmic Microwave Background…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Miguel Escudero , Héctor Ramírez , Lotfi Boubekeur , Elena Giusarma , Olga Mena

The reconstruction procedure, which has proven quite useful to obtain viable models of the universe evolution, is here employed in order to construct inflation models. It has the advantages that it ensures full consistency with astronomical…

High Energy Physics - Theory · Physics 2015-09-16 Rio Saitou , Emilio Elizalde

We discuss a new scenario for early cosmology, when inflationary de Sitter phase dynamically emergent. This genuine quantum effect occurs as a result of dynamics of the topologically nontrivial sectors in a (conjectured) strongly coupled…

High Energy Physics - Phenomenology · Physics 2014-08-13 Ariel R. Zhitnitsky

The reconstruction of an inflationary universe considering the parametrization of the scalar spectral index as a function of the number of $e-$folds in the framework of a modified Friedmann equation is analyzed. In this context, we examine…

General Relativity and Quantum Cosmology · Physics 2024-09-12 Ramon Herrera , Carlos Rios

We construct an analytic f(R) gravity model that unifies early-time inflation with late-time cosmic acceleration within a single covariant framework. At high curvature, the model reproduces a Starobinsky-like inflationary plateau, while at…

General Relativity and Quantum Cosmology · Physics 2025-09-18 M. V. Pradosh Keshav , Arun Kenath

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