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Related papers: Universality classes of inflation

200 papers

We show that the cosmological evolution of a scalar field in a potential can be obtained from a renormalisation group equation. The slow roll regime of inflation models is understood in this context as the slow evolution close to a fixed…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 P. Binetruy , E. Kiritsis , J. Mabillard , M. Pieroni , C. Rosset

The values of, and connection between, the cosmological observables of the primordial power spectrum tilt $n_s$ and the inflationary tensor to scalar ratio $r$ are key guideposts to the physics of inflation. Universality classes can be…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-18 Eric V. Linder

We extend previous classifications of inflationary models by means of their behaviour at large-N, where N is the number of e-foldings. In addition to the perturbative 1/N case, whose slow-roll parameters fall off as powers of 1/N, we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Juan Garcia-Bellido , Diederik Roest

We consider non-canonical generalizations of two classes of simple single-field inflation models. First, we study the non-canonical version of "ultra-slow roll" inflation, which is a class of inflation models for which quantum modes do not…

Astrophysics · Physics 2009-11-13 Konstantinos Tzirakis , William H. Kinney

We study the ultra slow roll model in the context of stochastic inflation. Using stochastic $\delta N$ formalism, we calculate the mean number of $e$-folds, the power spectrum, the bispectrum and the stochastic corrections into these…

High Energy Physics - Theory · Physics 2019-01-23 Hassan Firouzjahi , Amin Nassiri-Rad , Mahdiyar Noorbala

We study inflection point inflation using Singularity Theory, which relates degenerate critical points of functions to their local behavior. This approach illuminates universal features of small-field models and gives analytic control over…

High Energy Physics - Theory · Physics 2011-09-28 Sean Downes , Bhaskar Dutta , Kuver Sinha

We propose a class of single-field, slow-roll inflation models in which a typical number of $e$-folds can be extremely large. The key point is to introduce a very shallow local minimum near the top of the potential in a hilltop inflation…

High Energy Physics - Phenomenology · Physics 2019-12-16 Naoya Kitajima , Yuichiro Tada , Fuminobu Takahashi

We explore some issues in slow roll inflation in situations where field excursions are small compared to $M_p$. We argue that for small field inflation, minimizing fine tuning requires low energy supersymmetry and a tightly constrained…

High Energy Physics - Phenomenology · Physics 2015-05-30 Michael Dine , Lawrence Pack

Slow-roll inflation is studied as an effective field theory.We find as consistent form of the inflaton potential V(phi)=N M^4 w(phi/[sqrt{N}M_P]) where phi is the inflaton field, M the inflation energy scale, M_P the Planck mass, and N~50…

Astrophysics · Physics 2009-11-13 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

In constant-roll inflation, the scalar field that drives the accelerated expansion of the Universe is rolling down its potential at a constant rate. Within this framework, we highlight the relations between the Hubble slow-roll parameters…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-08 Alexandros Karam , Luca Marzola , Thomas Pappas , Antonio Racioppi , Kyriakos Tamvakis

Inflation is part of the Standard Model of the Universe supported by CMB and large scale structure LSS datasets. This review presents new developments of inflation in three main chapters. (I): The effective theory of inflation a la…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-13 D. Boyanovsky , C. Destri , H. J. de Vega , N. G. Sanchez

We derive a generalized expressions for the scalar power spectrum and the observational parameters of inflation (the scalar spectral index $n_{\rm s}$ and the tensor-to-scalar ratio $r$) for several single field scalar models minimally…

General Relativity and Quantum Cosmology · Physics 2024-09-25 Marko Stojanovic , Dragoljub D. Dimitrijevic , Milan Milosevic

Many, if not most, inflationary models predict the power-law index of the spectrum of density perturbations is close to one, though not precisely equal to one, |n-1| \sim O(0.1), implying that the spectrum of density perturbations is…

Astrophysics · Physics 2009-10-31 Dragan Huterer , Michael S. Turner

A study of the slow-roll inflation for an exponential potential in the frame of the scalar-tensor theory is performed, where non-minimal kinetic coupling to curvature and non-minimal coupling of the scalar field to the Gauss-Bonnet…

High Energy Physics - Theory · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

We study constant roll inflation systematically. This is a regime, in which the slow roll approximation can be violated. It has long been thought that this approximation is necessary for agreement with observations. However, recently it was…

High Energy Physics - Theory · Physics 2018-02-21 Lilia Anguelova , Peter Suranyi , L. C. Rohana Wijewardhana

We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multi field version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single…

Astrophysics · Physics 2013-05-29 Richard Easther , John T Giblin

I generalize the inflationary flow equations of Hoffman and Turner to arbitrary order in slow roll. This makes it possible to study the predictions of slow roll inflation in the full observable parameter space of tensor/scalar ratio $r$,…

Astrophysics · Physics 2009-11-07 William H. Kinney

We compute the tensor and scalar spectral index $n_t$, $n_s$, the tensor-to-scalar ratio $r$, the consistency relation $n_t/r$ in the general monomial multifield slow-roll inflation models with potentials $V \sim\sum_i\lambda_i…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-21 Zhong-Kai Guo

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

Generalized slow roll conditions and parameters are obtained for a general form of scalar-tensor theory (with no external sources), having arbitrary functions describing a nonminimal gravitational coupling F(\phi), a Kahler-like kinetic…

General Relativity and Quantum Cosmology · Physics 2009-11-07 J. R. Morris
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