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Related papers: The exact solution approach to warm inflation

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We study the inflationary scenario in the Tsallis entropy-based cosmology. The Friedmann equations in this setup can be derived by using the first law of thermodynamics. To derive the relations of the power spectra of the scalar and tensor…

General Relativity and Quantum Cosmology · Physics 2024-01-26 Zeinab Teimoori , Kazem Rezazadeh , Abasat Rostami

We study cosmological inflation in the Einstein gravity model, where additionally the Gauss-Bonnet term non-minimally coupled to a scalar field is included. We prove that inflationary solutions of exponential and power-law types are…

General Relativity and Quantum Cosmology · Physics 2017-12-06 Igor V. Fomin , Sergey V. Chervon

Discovered almost forty years ago, inflation has become the leading paradigm for the early universe. Originally invented to avoid the fine-tuning puzzles of the standard model of cosmology, the so-called hot Big Bang phase, inflation has…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-15 Jerome Martin

This paper discusses the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology. We show how, after a simple change of variables, to quantize the problem in a way which parallels the classical discussion. The result is…

High Energy Physics - Theory · Physics 2007-05-23 Marvin Weinstein , Ratindranath Akhoury

The main aim of this paper is to provide a qualitative introduction to the cosmic inflation and its relationship with current cosmological observations. The inflationary model solves many of the fundamental problems that challenge the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-24 J. Alberto Vazquez , Luis E. Padilla , Tonatiuh Matos

The standard model of cosmology is based on the hot Big Bang theory and the inflationary paradigm. Recent precise observations of the temperature and polarization anisotropies in the cosmic microwave background and the matter distribution…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-02 Juan Garcia-Bellido

An exact scalar field cosmological model is constructed from the exact solution of the field equations. The solutions are exact and no approximation like slow roll is used. The model gives inflation, solves horizon and flatness problems.…

General Physics · Physics 2011-12-14 Debasis Biswas

The description of the accelerated phases for the current and primordial cosmos has been obtained in the framework of R\'{e}nyi cosmology. The results show that corrections to the Friedmann equations, originated from differences between…

General Relativity and Quantum Cosmology · Physics 2019-09-05 H. Moradpour , A. H. Ziaie , V. B. Bezerra , S. Ghaffari

Modifying the standard hot big bang model of cosmology with an inflationary event has been very successful in resolving most of the outstanding cosmological problems. The various inflationary mechanisms proposed depend on the production of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Akinbo Ojo

One common approach for cosmic inflation consists in couple Einstein's gravity with a scalar field, often referred to inflaton field. In order to derive analytic simple scenarios, we usually work in the {\it slow-roll} regime. In such an…

General Relativity and Quantum Cosmology · Physics 2021-01-01 J. R. L. Santos , P. H. R. S. Moraes

Many pedagogical introductions of cosmological inflation are effective due to the simplicity of the relevant equations. Here an analytic solution of the cosmological equations is presented and used as an example to discuss fundamental…

Physics Education · Physics 2009-11-06 Valerio Faraoni

We consider a physically viable cosmological model that has a field dependent Gauss-Bonnet coupling in its effective action, in addition to a standard scalar field potential. The presence of such terms in the four dimensional effective…

High Energy Physics - Theory · Physics 2008-11-26 Ishwaree P Neupane , Benedict M N Carter

The previously proposed modification of the standard (flat) inflationary $\Lambda CDM$ model in which the inflaton field(s) and ``dark energy" are replaced by the vacum in expanding Friedmann-Lema\^itre-Robertson-Walker Universe is studied.…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Robert Alicki

We propose a method to extract predictions from quantum cosmology for inflation that can be confronted with observations. Employing the tunneling boundary condition in quantum geometrodynamics, we derive a probability distribution for the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Gianluca Calcagni , Claus Kiefer , Christian F. Steinwachs

We discuss a model of gravity coupled to a scalar field that admits exact cosmological solutions displaying an inflationary behavior at early times and a power-law expansion at late times.

General Relativity and Quantum Cosmology · Physics 2015-06-19 S. Mignemi , N. Pintus

The recently released data from the $\textit{Atacama Cosmology Telescope}$ (ACT) confirms that the primordial scalar spectrum is extremely flat. This, together with current upper bounds on the tensor-to-scalar ratio, implies that the…

High Energy Physics - Theory · Physics 2025-11-24 Arjun Berera , Suddhasattwa Brahma , Zizang Qiu , Rudnei O. Ramos , Gabriel S. Rodrigues

Scalar field cosmological inflation has a first integral relating the Hubble function and the lagrangian of the scalar field(s), which is known under the names of "Hamilton-Jacobi approach" or "superpotential equation". Here we exploit the…

General Relativity and Quantum Cosmology · Physics 2019-07-09 C. Adam , D. Varela

The present work examines the possibility of warm inflationary paradigm in the modified gravity theory with fractal geometry. By choosing the normal fluid as radiation fluid and the effective fluid (with the extra term in modified field…

General Relativity and Quantum Cosmology · Physics 2022-04-14 A. Bose , S. Chakraborty

Warm inflation is an inflationary scenario in which a thermal bath coexists with the inflaton during inflation. This is unlike standard cold inflation in which the Universe is effectively devoid of particles during inflation. The thermal…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Raghavan Rangarajan

A quantum field theory warm inflation model is presented that solves the cosmological horizon/flatness problems. An interpretation of the model is given from supersymmetry and superstring theory.

High Energy Physics - Phenomenology · Physics 2009-10-31 Arjun Berera