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The scenario of two components warm tachyon inflation is considered where the tachyon field plays the role of inflaton and drives inflation. During inflation, the tachyon scalar field interacts with the other component of the Universe which…

General Relativity and Quantum Cosmology · Physics 2020-07-02 Abolhassan Mohammadi , Tayeb Golanbari , Haidar Sheikhahmadi , Kosar Sayar , Lila Akhtari , M. A. Rasheed , Khaled Saaidi

The warm inflation scenario is an alternative mechanism which can explain the isotropic and homogeneous Universe which we are living in. In this work I extend a previously introduced formalism, without the restriction of slow - roll regime.…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Mauricio Bellini

We propose a new approach to constant-roll warm inflation as a generalization of constant-roll inflation. Based on the $\beta$-function formalism, it is shown that constant-roll warm inflation models with a natural end fall into…

General Relativity and Quantum Cosmology · Physics 2021-05-12 Ui Ri Mun

In this paper we introduce the "warm vector inflation" scenario. In warm inflation scenario radiation is produced during the inflation epoch and reheating is avoided. Slow-roll and perturbation parameters of this model are presented. We…

General Relativity and Quantum Cosmology · Physics 2015-06-17 M. R. Setare , V. Kamali

In this study, we investigate the full nonlinear dynamics of warm inflation driven by the quartic inflaton potential, avoiding any simplifying approximations. The thermal backreaction is incorporated through a dissipation coefficient that…

General Relativity and Quantum Cosmology · Physics 2025-11-20 Bhargabi Saha , Malay K. Nandy

The present work deals with a non-equilibrium thermodynamics that is associated with the scenario of warm inflation. The premise is that an adiabatic radiation production process holds exactly i.e. the radiation dilution is exactly…

General Relativity and Quantum Cosmology · Physics 2021-12-22 Akash Bose , Subenoy Chakraborty

We study slow-roll inflation model controlled by the modular flavor symmetry. In the model, the modulus field plays a role of inflaton and the introduction of the stabilizer field coupled to a modular form in the superpotential produces the…

High Energy Physics - Phenomenology · Physics 2023-07-26 Yoshihiko Abe , Tetsutaro Higaki , Fumiya Kaneko , Tatsuo Kobayashi , Hajime Otsuka

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

Inflation, as currently understood, requires the presence of fields with very flat potentials. Supersymmetric models in which supersymmetry breaking is communicated by supergravity naturally yield such fields, but the scales are typically…

High Energy Physics - Phenomenology · Physics 2009-10-30 Michael Dine , Antonio Riotto

The slow-roll approximation to inflation is ultimately justified by the presence of inflationary attractors for the orbits of the solutions of the dynamical equations in phase space. There are many indications that the inflaton field…

General Relativity and Quantum Cosmology · Physics 2011-08-11 Valerio Faraoni

We study the non-linear dynamics of an inflationary phase transition in a quartically self coupled inflaton model within the framework of a de Sitter background. Large N and Hartree non-perturbative approximations combined with…

High Energy Physics - Phenomenology · Physics 2014-11-17 D. Boyanovsky , D. Cormier , H. J. de Vega , R. Holman

We draw attention to the possibility that inflation (i.e. accelerated expansion) might continue after the end of slow roll, during a period of fast oscillations of the inflaton field \phi . This phenomenon takes place when a mild…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Thibault Damour , Viatcheslav F. Mukhanov

This research paper used a newly proposed strategy for finding the exact inflationary solutions to the Friedman equations in the context of Rastall theory of gravity (RTG), which is known as constant-roll warm inflation (CRWI). The…

General Relativity and Quantum Cosmology · Physics 2023-11-10 Rabia Saleem , Iqra Shahid , M. Israr Aslam , Abdul Wahab

We analyze the weak (2 sigma) evidence for a running spectral index seen in the three-year WMAP dataset and its implications for single field, slow roll inflation. We assume that the running is comparable to the central value found from the…

Astrophysics · Physics 2011-05-12 Richard Easther , Hiranya Peiris

A warm-intermediate inflationary universe model is studied in the presence of the Galileon coupling $G(\phi,X)=g(\phi)X$. General conditions required for successful inflation are deduced and discussed from the background and cosmological…

General Relativity and Quantum Cosmology · Physics 2019-07-24 Ramon Herrera , Nelson Videla , Marco Olivares

The $\alpha$-attractor models of inflation have remained one of the preferred inflationary models for nearly a decade now. The unique attractor nature of these models in the $n_s-r$ plane have put these models in the sweet-spot of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-04 Dibya Chakraborty , Suratna Das

The generic prediction for the perturbations generated during slow--roll, single--field inflation, as they appear in the cosmic microwave background (CMB), is a flat, close--to--Gaussian spectrum. We calculate the general solution for a…

Astrophysics · Physics 2007-05-23 S. Gupta

We present a model of inflation based on a racetrack model without flux stabilization. The initial conditions are set automatically through topological inflation. This ensures that the dilaton is not swept to weak coupling through either…

High Energy Physics - Theory · Physics 2008-11-26 Zygmunt Lalak , Graham G. Ross , Subir Sarkar

If a coupling between the inflaton and the Gauss-Bonnet term is introduced, many models of inflation that were ruled out by the most recent Planck data can be made viable again. The predictions for the scalar spectral index and…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Kamil Mudrunka , Kazunori Nakayama

Quantum fast-roll initial conditions for the inflaton which are different from the classical fast-roll conditions and from the quantum slow-roll conditions can lead to inflation that last long enough. These quantum fast-roll initial…

Astrophysics · Physics 2009-01-01 F. J. Cao , H. J. de Vega , N. G. Sanchez