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In this work, we analyze two possible alternative and model-independent approaches to describe the inflationary period. The first one assumes a general equation of state during inflation due to Mukhanov, while the second one is based on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-29 Lotfi Boubekeur , Elena Giusarma , Olga Mena , Héctor Ramírez

We study the two-phase scenario following inflation, where the initial step is preheating, accompanied by a step of perturbative reheating at which inflaton field decays transferring all of its energy to create relativistic particles, the…

General Relativity and Quantum Cosmology · Physics 2021-05-03 Khalil El Bourakadi

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

Based on the formulation of the reconstruction for the k-essence model, which was recently proposed in arXiv:1001.0220 [hep-th], we explicitly construct cosmological model to unifying the late-time acceleration and the inflation in the…

High Energy Physics - Theory · Physics 2015-05-19 Shin'ichi Nojiri

We propose a novel {\it k}-Gauss-Bonnet inflationary model, in which a kinetic term of scalar field is allowed to non-minimally couple to the Gauss-Bonnet topological invariant in the absence of a potential of scalar field. As a result,…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Tuyen M. Pham , Duy H. Nguyen , Tuan Q. Do

We present a numerical integration of the cosmological scalar perturbation equations in warm inflation. The initial conditions are provided by a discussion of the thermal fluctuations of an inflaton field and thermal radiation using a…

Astrophysics · Physics 2009-11-07 Lisa M. H. Hall , Ian G. Moss , Arjun Berera

A variant of hybrid inflation which is applicable in a wide class of supersymmetric grand unified models and reproduces the observed temperature perturbations of cosmic background radiation with natural values of the parameters is…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Lazarides

The precision reached by the recent CMB measurements gives new insights into the shape of the primordial power spectra of the cosmological perturbations. In the context of inflationary cosmology, this implies that the CMB data are now…

Astrophysics · Physics 2015-10-08 Christophe Ringeval

The very basics of cosmological inflation are discussed. We derive the equations of motion for the inflaton field, introduce the slow-roll parameters, and present the computation of the inflationary perturbations and their connection to the…

General Relativity and Quantum Cosmology · Physics 2012-01-31 K. Enqvist

We investigate a class of slow roll inflationary models in the light of the recent Cosmic Microwave Background constraints from Planck 2018, ACT DR6, DESI DR1, and BICEP/\textit{Keck} 2018. The combined dataset favors a higher value of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Suvashis Maity

The most current observational data corroborate the Starobinsky model as one of the strongest candidates in the description of an inflationary regime. Motivated by such success, extensions of the Starobinsky model have been increasingly…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 G. Rodrigues-da-Silva , J. Bezerra-Sobrinho , L. G. Medeiros

We develop a frame-covariant formulation of inflation in the slow-roll approximation by generalizing the inflationary attractor solution for scalar-curvature theories. Our formulation gives rise to new generalized forms for the potential…

High Energy Physics - Phenomenology · Physics 2016-06-22 Daniel Burns , Sotirios Karamitsos , Apostolos Pilaftsis

The Cosmic Microwave Background (CMB) observations results reported by {\it Planck} satellite suggest a plateau characteristic in the flat potential of the inflaton field is favored to drive the Universe's early acceleration. On that note,…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-10 Yogesh , Imtiyaz Ahmad Bhat , Mayukh R. Gangopadhyay

In this paper, we propose a new method to calculate the mode functions in the noncommutative power-law inflation model. In this model, all the modes created when the stringy space-time uncertainty relation is satisfied are generated inside…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Chao-Jun Feng , Xin-Zhou Li , Dao-Jun Liu

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

We confront the warm inflation observational predictions directly with the latest CMB data. We focus on a linear temperature (T) dissipative coefficient combined with the simplest model of inflation, a quartic chaotic potential. Although…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-06 Mar Bastero-Gil , Sukannya Bhattacharya , Koushik Dutta , Mayukh Raj Gangopadhyay

Models of cosmic inflation posit an early phase of accelerated expansion of the universe, driven by the dynamics of one or more scalar fields in curved spacetime. Though detailed assumptions about fields and couplings vary across models,…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-09 Alan H. Guth , David I. Kaiser , Yasunori Nomura

We study the primordial magnetic field generated by the simple model $f^2 FF$ in Starobinsky, $R^2$-inflationary, model. The scale invariant PMF is achieved at relatively high power index of the coupling function, $\left| \alpha \right|…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-21 Anwar Saleh AlMuhammad

We discuss the model selection problem for inflationary cosmology. We couple ModeCode, a publicly-available numerical solver for the primordial perturbation spectra, to the nested sampler MultiNest, in order to efficiently compute Bayesian…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-01 Richard Easther , Hiranya Peiris

Starobinsky inflation is an attractive, fundamental model to explain the Planck measurements, and its higher-order extension may allow us to probe quantum gravity effects. We show that future CMB data combined with the 21cm intensity map…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-30 Tanmoy Modak , Lennart Röver , Björn Malte Schäfer , Benedikt Schosser , Tilman Plehn
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