English
Related papers

Related papers: Inflationary Attractor from Tachyonic Matter

200 papers

Warm inflation in the framework of locally rotationally symmetric Bianchi type I universe model in the Hamilton-Jacobi formalism is being considered. Matter-Radiation fluid in warm inflation, endowed with and without a viscous pressure. For…

General Relativity and Quantum Cosmology · Physics 2023-10-25 M Tirandari , A Mohammadi

Several recent misconceptions about the measure problem in inflation and the nature of inflationary attractors are addressed. We show that within the Hamiltonian system of flat Friedmann-Lema\^itre-Robertson-Walker cosmology coupled to a…

General Relativity and Quantum Cosmology · Physics 2015-07-28 Alejandro Corichi , David Sloan

We prove the existence of a general class of rapidly turning two-field inflationary attractors. By only requiring a large, slowly varying turn rate, we solve the system completely without specifying any metric or potential, and prove the…

High Energy Physics - Theory · Physics 2019-07-03 Theodor Bjorkmo

We explore in detail the dynamics of multi-field inflationary models. We first revisit the two-field case and rederive the coordinate independent expression for the attractor solution with either small or large turn rate, emphasizing the…

High Energy Physics - Theory · Physics 2023-11-13 Perseas Christodoulidis , Robert Rosati

In this work, we study constant-roll inflation driven by a scalar field with non-minimal derivative coupling to gravity, via the Einstein tensor. This model contains a free parameter, $\eta$, which quantifies the non-minimal derivative…

General Relativity and Quantum Cosmology · Physics 2019-10-23 A. Oliveros , Hernán E. Noriega

A logamediate inflationary model in the presence of the tachyon scalar field will be studied. Considering slow-roll inflation, the equations of motion of the universe and the tachyon field will be derived. In the context of perturbation…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Arvin Ravanpak , Fahimeh Salmeh

We investigate in detail the attractor behavior of some inflationary models based on braneworld dynamics under the constant-roll condition. We describe the dynamics of the models, assuming that the second slow-roll parameter remains…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Goran S. Djordjevic , Neven Bilić , Dragoljub D. Dimitrijevic , Milan Milosevic , Marko Stojanovic

The tachyonic inflationary universe model in the context of intermediate inflation is studied. General conditions for this model to be realizable are discussed. In the slow-roll approximation, we describe in great details the…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Sergio del Campo , Ramon Herrera , Adolfo Toloza

We study flat FLRW $\alpha$-attractor $\mathrm{E}$- and $\mathrm{T}$-models by introducing a dynamical systems framework that yields regularized unconstrained field equations on two-dimensional compact state spaces. This results in both…

General Relativity and Quantum Cosmology · Physics 2017-04-26 Artur Alho , Claes Uggla

The slow-roll inflation paradigm can be systematically generalized within the framework of non-standard entropy formalisms, giving rise to a broad class of inflationary models that deviate from the conventional Bekenstein--Hawking case. We…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-26 H R M Zarandi , Esmaiel Ebrahimi , Yo Toda

Recently, several broad classes of inflationary models have been discovered whose cosmological predictions are stable with respect to significant modifications of the inflaton potential. Some classes of models are based on a non-minimal…

High Energy Physics - Theory · Physics 2015-04-16 Mario Galante , Renata Kallosh , Andrei Linde , Diederik Roest

Slow-roll inflationary scenario is considered in non-canonical scalar field model supposing a power-law function for kinetic term, and using two formalisms. In the first approach, the potential is considered as a power-law function, that is…

General Relativity and Quantum Cosmology · Physics 2017-08-15 Kh. Saaidi , A. Mohammadi , T. Golanbari

We study the structural stability of tachyonic inflation against changes in the shape of the potential. Following Lidsey (Gen. Rel. Grav. 25 (1993) 399), the concepts of rigidity and fragility are defined through a condition on the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. M. Aguirregabiria , Ruth Lazkoz

In negatively curved field spaces, inflation can be realised even in steep potentials. Hyperinflation invokes the `centrifugal force' of a field orbiting the hyperbolic plane to sustain inflation. We generalise hyperinflation by showing…

High Energy Physics - Theory · Physics 2019-05-22 Theodor Bjorkmo , M. C. David Marsh

We analyse the evolution of the reduced density matrix of inflationary perturbations, coupled to a heavy entropic field via the leading-order term within the Effective Field Theory of Inflation, for two nearly de Sitter backgrounds. We…

High Energy Physics - Theory · Physics 2024-11-14 Suddhasattwa Brahma , Jaime Calderón-Figueroa , Xiancong Luo , David Seery

We develop a method to compute the slow-roll expansion for the Hubble parameter in inflationary models in a flat Friedmann-Lema\^itre-Robertson-Walker spacetime that is applicable to a wide class of potentials including monomial,…

General Relativity and Quantum Cosmology · Physics 2024-10-07 Gabriel Álvarez , Elena Medina

We study an inflationary scenario with a vector field coupled with an inflaton field and show that the inflationary universe is endowed with anisotropy for a wide range of coupling functions. This anisotropic inflation is a tracking…

High Energy Physics - Theory · Physics 2009-06-30 Masa-aki Watanabe , Sugumi Kanno , Jiro Soda

Using Hamilton-Jacobi formalism, The scenario of warm inflation with viscous pressure is considered. The formalism gives a way of computing the slow-rolling parameters without extra approximation, and it is well-known as a powerful method…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 L. Akhtari , A. Mohammadi , K. Sayar , Kh. Saaidi

We compare the standard single scalar field inflationary predictions with those of an inflationary phase driven by a tachyon field. A slow-roll formalism is defined for tachyon inflation, and we derive the spectra of scalar and tensor…

High Energy Physics - Theory · Physics 2008-11-26 D. A. Steer , F. Vernizzi

We study the main properties of the warm inflationary model based on Barrow's solution for the scale factor of the universe. Within this framework we calculate analytically the basic slow roll parameters for different versions of warm…

General Relativity and Quantum Cosmology · Physics 2016-10-12 Vahid Kamali , Spyros Basilakos , Ahmad Mehrabi