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Related papers: Inflation in a viscous fluid model

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We review the connection between inflationary models and observations and concentrate to describe models based on softly broken supersymmetry, in particular running mass models, and their predictions. We then present a fit of the spectral…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laura Covi

In this review I consider several different issues related to inflation. I will begin with the wave function of the Universe. This issue is pretty old, but recently there were some new insights based on the theory of the self-reproducing…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Andrei Linde

We generalize the scalar-curvature coupling model ${\xi \Phi^2 R}$ of Higgs inflation to $ {\xi \Phi^a R^b} $ to study inflation. We compute the amplitude and spectral index of curvature perturbations generated during inflation and fix the…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-21 Girish Chakravarty , Subhendra Mohanty , Naveen K. Singh

Based on the conventional metric tensor and driven by a nearly constant energy density, cosmic inflation, characterized by a remarkably accelerated expansion, was proposed as an early epoch in the Universe. The energy density is typically…

General Relativity and Quantum Cosmology · Physics 2026-05-05 Swapnil K. Singh , Saleh O. Allehabi , Azzah A. Alshehri , Mahmoud Nasar , Abdel Nasser Tawfik

The amplitude of primordial curvature perturbations is enhanced when a radiation bath at a temperature T>H is sustained during inflation by dissipative particle production, which is particularly significant when a non-trivial statistical…

High Energy Physics - Phenomenology · Physics 2014-04-03 Sam Bartrum , Mar Bastero-Gil , Arjun Berera , Rafael Cerezo , Rudnei O. Ramos , Joao G. Rosa

By using the relations between the slow-roll parameters and the power spectrum for the single field slow-roll inflation, we derive the scalar spectral tilt $n_s$ and the tensor to scalar ratio $r$ for the constant slow-roll inflation and…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 Qing Gao

In this work, we solved the scalar and tensor perturbation equations numerically and using the improved uniform approximation method together with the third-order phase-integral method, for the $\alpha$-attractor inflationary model. This…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Jordan Zambrano , Miguel Agama , Marcos Garzón , Werner Bramer-Escamilla , Clara Rojas , Teófilo Vargas

We perform a general analysis of the cosmological viability of Geometric Inflation. We show that the evolution of the universe, from inflation to the present day, can be seen from the addition of an infinite tower of curvature invariants…

General Relativity and Quantum Cosmology · Physics 2021-09-27 Luisa G. Jaime

The Eisenhart lift allows to formulate the dynamics of a scalar field in a potential as pure geodesic motion in a curved field-space manifold involving an additional fictitious vector field. Making use of the formalism in the context of…

General Relativity and Quantum Cosmology · Physics 2023-08-02 Georgios K. Karananas , Marco Michel , Javier Rubio

We consider cosmological scenarios in which density perturbations are generated by the quantum fluctuations of the inflaton field at early times; the late time dynamics involves a modulus which first dominates the energy density of the…

High Energy Physics - Phenomenology · Physics 2015-03-09 Koushik Dutta , Anshuman Maharana

Inflationary scenarios motivated by high-energy physics generically contain a plethora of degrees of freedom beyond the primordial curvature perturbation. The latter interacts in a simple way with what we name "inflationary flavor…

High Energy Physics - Theory · Physics 2023-01-23 Lucas Pinol , Shuntaro Aoki , Sébastien Renaux-Petel , Masahide Yamaguchi

Using techniques from loop quantum gravity, the standard theory of cosmological perturbations was recently generalized to encompass the Planck era. We now apply this framework to explore pre-inflationary dynamics. The framework enables us…

General Relativity and Quantum Cosmology · Physics 2015-03-12 Ivan Agullo , Abhay Ashtekar , William Nelson

Warm inflation model with bulk viscous pressure in the context of "intermediate inflation" where the cosmological scale factor expands as $a(t)=a_0\exp(At^f)$, is studied. The characteristics of this model in slow-roll approximation and in…

General Relativity and Quantum Cosmology · Physics 2015-06-18 M. R. Setare , V. Kamali

There exists a growing body of observational evidence supporting a non-vanishing cosmological constant at the present epoch. We examine the possibility that such a term may arise directly from the potential energy which drove an…

Astrophysics · Physics 2014-10-13 Richard A. Frewin , James E. Lidsey

We revisit spectator field models including curvaton and modulated reheating scenarios, specifically focusing on their viability in the new Planck era, based on the derived expression for the spectral index in general spectator field…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-23 Takeshi Kobayashi , Fuminobu Takahashi , Tomo Takahashi , Masahide Yamaguchi

The simplicity of the CMB data, so well described by single-field inflation, raises the question whether there might be an equally simple multi-field realization consistent with the observations. We explore the idea that an approximate…

High Energy Physics - Theory · Physics 2019-07-04 Ana Achucarro , Yvette Welling

Some of the consequences for inflationary cosmology of a scale dependence (running) in the tilt of the scalar perturbation spectrum are considered. In the limit where the running is itself approximately scale-invariant, a relationship is…

Astrophysics · Physics 2015-06-24 James E. Lidsey , Reza Tavakol

In the standard cosmological picture the Universe underwent a brief period of near-exponential expansion, known as Inflation. This provides an explanation for structure formation through the amplification of perturbations by the rapid…

General Relativity and Quantum Cosmology · Physics 2019-04-03 Zack Fifer , Theo Torres , Sebastian Erne , Anastasios Avgoustidis , Richard J. A. Hill , Silke Weinfurtner

We propose a new four-parameter entropy function that generalizes the Tsallis, R\'{e}nyi, Barrow, Sharma-Mittal, Kaniadakis and Loop Quantum Gravity entropies for suitable limits of the parameters. Consequently, we address the early and…

General Relativity and Quantum Cosmology · Physics 2022-06-15 Shin'ichi Nojiri , Sergei D. Odintsov , Tanmoy Paul

Inspired by the reconstruction scheme of the inflaton field potential $V(\phi)$ from the attractors$n_s(N)$, we investigate the viability of reconstruct the inflationary potential within the framework of k-inflation for a non-linear kinetic…

General Relativity and Quantum Cosmology · Physics 2023-05-10 Ramon Herrera , Michel Housset , Constanza Osses , Nelson Videla