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Related papers: Formalising the Slow-Roll Approximation in Inflati…

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Brief periods of non-slow-roll evolution during inflation can produce interesting observable consequences, as primordial black holes, or an inflationary gravitational wave spectrum enhanced at small scales. We develop a model independent,…

High Energy Physics - Theory · Physics 2021-06-29 Gianmassimo Tasinato

In this paper we revisit the relationship between the Einstein--Friedman and the Abel equations to demonstrate how it might be applied to the inflationary analysis in a flat Friedman universe filled with a real-valued scalar field. The…

General Relativity and Quantum Cosmology · Physics 2019-07-30 Anna V. Yaparova , Artyom V. Yurov , Valerian A. Yurov

We study constant-roll inflation using the $\beta$-function formalism. We show that the constant rate of the inflaton roll is translated into a first order differential equation for the $\beta$-function which can be solved easily. The…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-09 F. Cicciarella , J. Mabillard , M. Pieroni

In this work we study slow-roll inflation for a vector-tensor model with massive vector fields non-minimally coupled to gravity. The model under consideration has arbitrary parameters for each geometrical coupling. Taking into account a…

General Relativity and Quantum Cosmology · Physics 2016-12-21 A. Oliveros

We compute the rate with which super-Hubble cosmological fluctuations are decohered during inflation, by their gravitational interactions with unobserved shorter-wavelength scalar and tensor modes. We do so using Open Effective Field Theory…

High Energy Physics - Theory · Physics 2023-07-12 C. P. Burgess , R. Holman , Greg Kaplanek , Jerome Martin , Vincent Vennin

The observational constraints on the primordial power spectrum have tightened considerably with the release of the first year analysis of the WMAP observations, especially when combined with the results from other CMB experiments and galaxy…

High Energy Physics - Phenomenology · Physics 2009-11-10 Dominik J. Schwarz , Cesar A. Terrero-Escalante

We investigate the relationship between the holographic temperature bound and the slow-roll inflation. For this purpose we introduce the holographic temperature bound for a radiation matter :$T \ge T_{\rm H}$. Here $T_{\rm H}$ is the Hubble…

High Energy Physics - Theory · Physics 2007-05-23 Y. S. Myung

Inflation is the currently accepted paradigm for the beginnings of the Universe. To explain the observed almost scale invariant spectrum of density perturbations with only a slight spectral tilt, inflation must have been "slow roll", that…

High Energy Physics - Theory · Physics 2021-01-07 Hao Geng

We extend the warm inflationary scenario to the case of the noncanonical scalar fields. The equation of motion and the other basic equations of this new scenario are obtained. The Hubble damped term is enhanced in noncanonical inflation. A…

General Relativity and Quantum Cosmology · Physics 2014-12-24 Xiao-Min Zhang , Jian-Yang Zhu

In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-25 Dries Coone , Diederik Roest , Vincent Vennin

We consider inflation using a class of non-canonical Lagrangians for which the modification to the kinetic term depends on the field, but not its derivatives. We generalize the standard Hubble slow roll expansion to the non-canonical case…

Astrophysics · Physics 2010-10-27 Gabriela Barenboim , William H. Kinney

We consider the classical wave equation with a thermal and Starobinsky-Vilenkin noise which in a slow-roll and long wave approximation describes the quantum fluctuations of the graviton-inflaton system in an expanding metric. We investigate…

General Relativity and Quantum Cosmology · Physics 2019-11-13 Z. Haba

Based on the entropy of anti-de Sitter black hole, a new holographic dark energy model has been proposed. When the Hubble horizon and particle horizon are chosen as the IR cutoff, the late-time accelerated expansion of universe is realized.…

General Relativity and Quantum Cosmology · Physics 2025-04-16 Qihong Huang , He Huang , Bing Xu , Kaituo Zhang

In this note we point out that, contrary to the standard point of view, slow roll inflation is due to high gravitational friction. We show that the requirement of slow roll coincides with the requirement of a flat scalar field potential in…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-07 Cristiano Germani

We construct approximate inflationary solutions rolling away from the unstable maximum of p-adic string theory, a nonlocal theory with derivatives of all orders. Novel features include the existence of slow-roll solutions even when the…

High Energy Physics - Theory · Physics 2010-10-27 Neil Barnaby , Tirthabir Biswas , James M. Cline

We investigate how a Type IV future singularity can be included in the cosmological evolution of a well-known exponential model of inflation. In order to achieve this we use a two scalar field model, in the context of which the…

General Relativity and Quantum Cosmology · Physics 2015-07-21 S. D. Odintsov , V. K. Oikonomou

We point out that the theoretical predictions for the inflationary observables may be generically altered by the presence of fields which are heavier than the Hubble rate during inflation and whose dynamics is usually neglected. They…

Astrophysics · Physics 2009-06-23 N. Bartolo , A. Riotto

We provide a precise and quantitative holographic description of a class of inflationary slow-roll models. The dual QFT is a deformation of a three-dimensional CFT by a nearly marginal operator, which, in the models we consider, generates…

High Energy Physics - Theory · Physics 2013-08-28 Adam Bzowski , Paul McFadden , Kostas Skenderis

The slow rolling inflation is dual to the random walk of conformal zero-mode. The 2 dimensional Fokker-Planck theory predicts the slow roll parameters of 4d inflation theory. The O(N) enhancements of the two point functions, N is the…

High Energy Physics - Theory · Physics 2023-05-02 Yoshihisa Kitazawa

From the assumption that the slow roll parameter $\epsilon$ has a Lorentzian form as a function of the e-folds number $N$, a successful model of a quintessential inflation is obtained, as succinctly studied in \cite{Benisty:2020xqm}. The…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-07 David Benisty , Eduardo I. Guendelman