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Related papers: Inflaton potential reconstruction without slow-rol…

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We use the PLANCK 2018 and the WMAP data to constraint inflation models driven by a scalar field $\phi$ in the presence of the non-minimal scalar-curvature mixing term $\frac{1}{2}\xi R \phi^2$. We consider four distinct scalar field…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-26 Payel Sarkar , Ashmita , Prasanta Kumar Das

In this paper we develop the formalism for the stochastic approach to inflation at all order in slow-roll parameters. This is done by including the momentum and Hamiltonian constraints into the stochastic equations. We then specialise to…

General Relativity and Quantum Cosmology · Physics 2022-02-09 Diego Cruces , Cristiano Germani

We study slow-roll inflation with a Gauss-Bonnet term that is coupled to an inflaton field nonminimally. We investigate the inflationary solutions for a specific type of the nonminimal coupling to the Gauss-Bonnet term and inflaton…

General Relativity and Quantum Cosmology · Physics 2014-10-08 Seoktae Koh , Bum-Hoon Lee , Wonwoo Lee , Gansukh Tumurtushaa

We present constraints on inflationary dynamics and features in the primordial power spectrum of scalar perturbations using the Cosmic Microwave Background temperature, polarization data from Planck 2018 data release and updated…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-28 Dhiraj Kumar Hazra , Daniela Paoletti , Ivan Debono , Arman Shafieloo , George F. Smoot , Alexei A. Starobinsky

The scalar perturbations in inflationary models, based on a two-component diagonal non-linear sigma model, are considered. For inhomogeneities generated at an inflationary stage, the law of motion of the comoving curvature ${\cal R}$ is…

Astrophysics · Physics 2007-05-23 N. A. Koshelev

We consider slow-roll inflation in the context of a modified Brans-Dicke dilaton gravity. From a two self-interacting potentials $V(\phi)$, we reproduce a Starobinsky-like potential and, commonly in syperstring models, an exponential tail…

General Relativity and Quantum Cosmology · Physics 2024-11-11 Abraão J. S. Capistrano , Gilberto M. Kremer

We consider inflation with a constant rate of rolling in which a complex scalar field plays the role of inflaton during the inflationary epoch. We implement the inflationary analysis for an accredited angular speed $\dot{\theta}$ which…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Ramón Herrera , Mehdi Shokri , Jafar Sadeghi

We review the relation between the inflationary potential and the spectra of density (scalar) perturbations and gravitational waves (tensor perturbations) produced, with particular emphasis on the possibility of reconstructing the inflaton…

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

The inflaton field responsible for inflation may not be a canonical fundamental scalar. It is possible that the inflaton is a composite of fermions or it may have a decay width. In these cases the standard procedure for calculating the…

High Energy Physics - Phenomenology · Physics 2009-09-28 Suratna Das , Subhendra Mohanty

We introduce a new method for applying an inflationary prior to a cosmological dataset that includes relations between observables at arbitrary order in the slow roll expansion. The process is based on the inflationary flow equations, and…

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

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

We revisit the notion of slow-roll in the context of general single-field inflation. As a generalization of slow-roll dynamics, we consider an inflaton $\phi$ in an attractor phase where the time derivative of $\phi$ is determined by a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jinn-Ouk Gong , Misao Sasaki

We study Quadratic Inflation with the inflaton field $\phi$ coupled non-minimally to the curvature scalar $R$, so that the potential during inflation is of the form $V\propto m^2\phi^2+\xi R\phi^2$. We show that with a suitable choice of…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-13 Tommi Tenkanen

We construct an inflation model with inflaton non-minimally coupled to gravity on a warped DGP brane. Using an exponential potential, we calculate scalar power spectrum, spectral index and the running of the spectral index. We show that for…

High Energy Physics - Theory · Physics 2009-06-11 Kourosh Nozari , Behnaz Fazlpour

A possible origin of the anomalous dip and bump in the primordial power spectrum, which are reconstructed from WMAP data corresponding to the multipole $\ell=100\sim 140$ by using the inversion method, is investigated as a consequence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Kohei Kumazaki , Shuichiro Yokoyama , Naoshi Sugiyama

Stochastic inflation, together with the $\Delta N$ formalism, provides a powerful tool for estimating the large-scale behaviour of primordial fluctuations. In this work, we develop a numerical code to capture the non-perturbative statistics…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-10 Devanshu Sharma

We study a supergravity model of inflation essentially depending on one parameter which can be identified with the slope of the potential at the origin. In this type of models the inflaton rolls at high energy from negative values and a…

Astrophysics · Physics 2009-11-10 G. German , A. de la Macorra

We derive an expression for the non-Gaussian cosmic-microwave-background (CMB) statistic $I_l^3$ defined recently by Ferreira, Magueijo, and G\'orski in terms of the slow-roll-inflation parameters $\epsilon$ and $\eta$. This result shows…

Astrophysics · Physics 2011-02-02 Limin Wang , Marc Kamionkowski

We use cosmic microwave background and large scale structure data to test a broad and physically well-motivated class of inflationary models: those with flat tree-level potentials (typical in supersymmetry). The non-trivial features of the…

High Energy Physics - Phenomenology · Physics 2009-03-24 G. Ballesteros , J. A. Casas , J. R. Espinosa , R. Ruiz de Austri , R. Trotta
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