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Related papers: Inflationary Attractor from Tachyonic Matter

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We construct models with the Gauss-Bonnet term multiplied to a function of the scalar field leading to inflationary scenario. The consideration is related with the slow-roll approximation. The cosmological attractor approach gives the…

General Relativity and Quantum Cosmology · Physics 2020-07-29 E. O. Pozdeeva

We propose a 3 + 1 dimensional model of gravity which results in inflation at early times, followed by radiation- and matter-dominated epochs and a subsequent acceleration at late times. Both the inflation and late time acceleration are…

High Energy Physics - Theory · Physics 2015-05-30 Carlos Herdeiro , Shinji Hirano

In this paper we find a solution for a quasi-isotropic inflationary Universe which allows to introduce in the problem a certain degree of inhomogeneity. We consider a model which generalize the (flat) FRW one by introducing a first order…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giovanni Paolo Imponente , Giovanni Montani

Rapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-06 Raul Wolters , Oksana Iarygina , Ana Achucarro

We consider a warm inflationary scenario in which the two dominant matter components present in the early Universe, the scalar field, and the radiation fluid, evolve with different four-velocities. This cosmological system is mathematically…

General Relativity and Quantum Cosmology · Physics 2021-03-15 Tiberiu Harko , Haidar Sheikhahmadi

We systematically study the preinflationary dynamics of the spatially flat Friedmann-Lemaitre-Robertson-Walker universe filled with a single scalar field that has the generalized $\alpha-$attractor potentials, in the framework of loop…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-29 M. Shahalam , M. Sami , Anzhong Wang

We present a model for cosmological inflation which has a natural "turn on" and a natural "turn off" mechanism. In our model inflation is driven by the Hawking-like radiation that occurs in Friedman-Robertson-Walker (FRW) space-time. This…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Sujoy Kumar Modak , Douglas Singleton

We study inflation in the $\alpha-$attractor model under a non-slow-roll dynamics with an ansatz proposed by Gong \& Sasaki \cite{Gong:2015ypa} of assuming $N=N\left(\phi\right)$. Under this approach, we construct a class of local shapes of…

General Relativity and Quantum Cosmology · Physics 2017-11-21 K. Sravan Kumar , João Marto , Paulo Vargas Moniz , Suratna Das

Warm inflationary universe models in a tachyon field theory are studied. General conditions required for these models to be realizable are derived and discussed. We describe scalar perturbations (in the longitudinal gauge) and tensor…

Astrophysics · Physics 2009-11-11 R. Herrera , S. del Campo , C. Campuzano

We study the non-linear dynamics of axion inflation, capturing for the first time the inhomogeneity and full dynamical range during strong backreaction, till the end of inflation. Accounting for inhomogeneous effects leads to a number of…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-01 Daniel G. Figueroa , Joanes Lizarraga , Ander Urio , Jon Urrestilla

A generalization of the canonical and non-canonical theory of inflation is introduced in which the kinetic energy term in action is written as non-local term. The inflationary universe within the framework of considering this non-locality…

General Relativity and Quantum Cosmology · Physics 2015-07-01 Haidar Sheikhahmadi , Soheyla Ghorbani , Khaled Saaidi

It has been widely claimed that inflation is generically eternal to the future, even in models where the inflaton potential monotonically increases away from its minimum. The idea is that quantum fluctuations allow the field to jump uphill,…

High Energy Physics - Theory · Physics 2009-11-11 Steven Gratton , Neil Turok

We constrain several models in Tachyonic Inflation derived from the large-$N$ formalism by considering theoretical aspects as well as the latest observational data. On the theoretical side, we assess the field range of our models by means…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-22 Nandinii Barbosa-Cendejas , Josue De-Santiago , Gabriel German , Juan Carlos Hidalgo , Refugio Rigel Mora-Luna

Tachyonic preheating is realized when the inflaton repeatedly returns to a convex region of the potential during the post-inflationary oscillating phase. This will induce a strong tachyonic instability and lead to a rapid fragmentation of…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Niko Koivunen , Eemeli Tomberg , Hardi Veermäe

Classifying inflationary scenarios according to their scaling properties is a powerful way to connect theory with observations. A useful tool to make such a classification is the beta-function formalism. By describing inflation in terms of…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-02 Francesco Cicciarella , Joel Mabillard , Mauro Pieroni , Angelo Ricciardone

The hypothesis of low entropy in the initial state of the universe usually explains the observed entropy increase is in only one time direction: the thermodynamic arrow of time. The Hamiltonian formalism is commonly used in the context of…

General Relativity and Quantum Cosmology · Physics 2024-08-27 Jackie C. H. Liu

A quantum field theory warm inflation model is presented that solves the horizon/flatness problems. The model obtains, from the elementary dynamics of particle physics, cosmological scale factor trajectories that begin in a radiation…

High Energy Physics - Phenomenology · Physics 2008-11-26 Arjun Berera , Marcelo Gleiser , Rudnei O. Ramos

It is shown that the inflationary era in early universe is realized due to the effect of backreaction of quantized matter fields. In fact we start by quantizing a free scalar field in the Friedmann-Robertson-Walker space-time, and the field…

High Energy Physics - Theory · Physics 2015-06-23 Yoshinobu Habara , Hikaru Kawai , Masao Ninomiya

This paper is devoted to study the warm inflation using vector fields in the background of locally rotationally symmetric Bianchi type I universe model. We formulate the field equations, slow-roll and perturbation parameters (scalar and…

General Relativity and Quantum Cosmology · Physics 2015-06-18 M. Sharif , Rabia Saleem

Inflationary models are generally credited with explaining the large scale homogeneity, isotropy, and flatness of our universe as well as accounting for the origin of structure (i.e., the deviations from exact homogeneity) in our universe.…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Stefan Hollands , Robert M. Wald