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Related papers: Correlation Functions in Stochastic Inflation

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We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which…

Astrophysics · Physics 2010-10-27 Xingang Chen , Richard Easther , Eugene A. Lim

We elucidate the counting of the relevant small parameters in inflationary perturbation theory. Doing this allows for an explicit delineation of the domain of validity of the semi-classical approximation to gravity used in the calculation…

High Energy Physics - Theory · Physics 2018-02-21 Peter Adshead , C. P. Burgess , R. Holman , Sarah Shandera

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…

Astrophysics · Physics 2016-11-09 Filippo Vernizzi , Daniele Steer

We study multifield contributions to the scalar power spectrum in an ensemble of six-field inflationary models obtained in string theory. We identify examples in which inflation occurs by chance, near an approximate inflection point, and we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Liam McAllister , Sébastien Renaux-Petel , Gang Xu

Scattering amplitudes at weak coupling are highly constrained by Lorentz invariance, locality and unitarity, and depend on model details only through coupling constants and particle content. In this paper, we develop an understanding of…

High Energy Physics - Theory · Physics 2019-11-01 Nima Arkani-Hamed , Daniel Baumann , Hayden Lee , Guilherme L. Pimentel

Using the \delta N formalism we consider the non-linear curvature perturbation in multi-field models of inflation with non-minimal coupling. In particular, we focus on the relation between the \delta N formalism as applied in the…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-25 Jonathan White , Masato Minamitsuji , Misao Sasaki

Soft limits of inflationary correlation functions are both observationally relevant and theoretically robust. Various theorems can be proven about them that are insensitive to detailed model-building assumptions. In this paper, we re-derive…

High Energy Physics - Theory · Physics 2015-06-04 Valentin Assassi , Daniel Baumann , Daniel Green

By using the relations between the slow-roll parameters and the power spectrum for the single field slow-roll inflation, we derive the scalar spectral tilt $n_s$ and the tensor to scalar ratio $r$ for the constant slow-roll inflation and…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 Qing Gao

During inflation explicit perturbative computations of quantum field theories which contain massless, non-conformal fields exhibit secular effects that grow as powers of the logarithm of the inflationary scale factor. Starobinskii's…

General Relativity and Quantum Cosmology · Physics 2009-11-11 N. C. Tsamis , R. P. Woodard

The calculation of scalar gravitational and matter perturbations during multiple-field inflation valid to first order in slow roll is discussed. These fields may be the coordinates of a non-trivial field manifold and hence have non-minimal…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. J. W. van Tent , S. Groot Nibbelink

We extend the formalism of stochastic inflation to the setup of non-attractor inflation with a sound speed $c_s$. We obtain the Langevin equations for the superhorizon perturbations and calculate the stochastic corrections to curvature…

High Energy Physics - Theory · Physics 2020-12-09 Hassan Firouzjahi , Amin Nassiri-Rad , Mahdiyar Noorbala

The delta N formula that relates the final curvature perturbation on comoving slices to the inflaton perturbation on flat slices after horizon crossing is a powerful and intuitive tool to compute the curvature perturbation spectrum from…

Astrophysics · Physics 2009-10-09 Hyun-Chul Lee , Misao Sasaki , Ewan D. Stewart , Takahiro Tanaka , Shuichiro Yokoyama

We use the power-counting formalism of effective field theory to study the size of loop corrections in theories of slow-roll inflation, with the aim of more precisely identifying the limits of validity of the usual classical inflationary…

High Energy Physics - Phenomenology · Physics 2009-10-17 C. P. Burgess , Hyun Min Lee , Michael Trott

The delta-N formalism is considered to calculate the evolution of the curvature perturbation in generalized multi-field inflation models. The result is consistent with the usual calculation of the standard kinetic term. For the calculation…

High Energy Physics - Theory · Physics 2009-11-23 Tomohiro Matsuda

We use the dS/CFT correspondence and bulk gravity to predict the form of the renormalized holographic three-point correlation function of the operator which is dual to the inflaton field perturbation during single-field, slow-roll…

Astrophysics · Physics 2007-05-23 David Seery , James E. Lidsey

Slow-roll inflation can be studied as an effective field theory. The form of the inflaton potential consistent with the data is V(phi) = N M^4 w(phi/[sqrt{N} M_{Pl}]) where phi is the inflaton field, M is the inflation energy scale, and N ~…

Astrophysics · Physics 2007-05-23 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

One of the fundamental objectives of contemporary cosmology is to understand the physics of the inflationary universe, owing to its observably verifiable predictions about the very early universe with an energy scale of $\sim 10^{16}$ GeV.…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-14 Aayush Randeep , Rajib Saha

We analyse the dynamics of spinodal decomposition in inflationary cosmology using the closed time path formalism of out of equilibrium quantum field theory combined with the non-perturbative Hartree approximation. In addition to a general…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Cormier , R. Holman

Utilizing the Maldacena formalism and extending the earlier efforts to compute the scalar bi-spectrum, we construct a numerical procedure to evaluate the three-point scalar-tensor cross-correlations as well as the tensor bi-spectrum in…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-17 V. Sreenath , Rakesh Tibrewala , L. Sriramkumar

We review recent developments in the theory of inflation and cosmological perturbations produced from inflation. After a brief introduction of the standard, single-field slow-roll inflation, and the curvature and tensor perturbations…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-31 Misao Sasaki