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Motivated by the possibility of inflation in the cosmic landscape, which may be approximated by a complicated potential, we study the density perturbations in multi-field inflation with a random potential. The random potential causes the…

High Energy Physics - Theory · Physics 2009-04-24 S. -H. Henry Tye , Jiajun Xu , Yang Zhang

We calculate the quadra-spectrum and quint-spectrum, corresponding to five and six point correlation functions of the curvature perturbation. For single field inflation with standard kinetic term, the quadra-spectrum and quint-spectrum are…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-16 Chunshan Lin , Yi Wang

We construct a multi-field inflationary model consisting of multiple K\"ahler moduli derived from type IIB string compactification in the large volume limit. The model consists of both heavy and light fields, with the former being frozen…

High Energy Physics - Theory · Physics 2009-12-09 Per Berglund , Guoqin Ren

We explore inflationary trajectories within randomly-generated two-dimensional potentials, considered as a toy model of the string landscape. Both the background and perturbation equations are solved numerically, the latter using the…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Jonathan Frazer , Andrew R Liddle

We outline the modifications in the numerical Boltzmann code Cosmic Linear Anisotropy Solving System (CLASS) in order to include extra inflationary fields. The functioning of the code is first described, how and where modifications are…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-21 Braulio Morales-Martínez , Gustavo Arciniega , Luisa G. Jaime , Gabriella Piccinelli

Inflation offers a simple model for very early evolution of our Universe and the origin of primordial perturbations on large scales. Over the last 25 years we have become familiar with the predictions of single-field models, but inflation…

Astrophysics · Physics 2008-11-26 David Wands

We investigate the dynamics of the recently proposed model of assisted inflation. In this model an arbitrary number of scalar fields with exponential potentials evolve towards an inflationary scaling solution, even if each of the individual…

Astrophysics · Physics 2016-08-25 Karim A. Malik , David Wands

We study the power spectra and entropy of two-field warm inflationary scenario with canonical condition which is described by many-dimensional stochastic differential equations. The field perturbations are analytically calculated via a…

General Relativity and Quantum Cosmology · Physics 2019-03-12 Xi-Bin Li , Xiao-Gang Zheng , Jian-Yang Zhu

We develop a covariant method for studying the effects of a reheating phase on the primordial adiabatic and isocurvature perturbations in two-field models of inflation. To model the decay of the scalar fields into radiation at the end of…

High Energy Physics - Theory · Physics 2018-12-12 Pablo González , Gonzalo A. Palma , Nelson Videla

CppTransport is a numerical platform that can automatically generate and solve the evolution equations for the 2- and 3-point correlation functions (in field space and for the curvature perturbation) for any inflationary model with…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-05 David Seery

Motivated by the prospect of testing inflation from precision cosmic microwave background observations, we present analytic results for scalar and tensor perturbations in single-field inflation models based on the application of uniform…

Astrophysics · Physics 2009-11-07 Salman Habib , Katrin Heitmann , Gerard Jungman , Carmen Molina-Paris

We propose a general inverse formula for extracting inflationary parameters from the observed power spectrum of cosmological perturbations. Under the general slow-roll scheme, which helps to probe the properties of inflation in a model…

Astrophysics · Physics 2009-11-10 Minu Joy , Ewan D. Stewart , Jinn-Ouk Gong , Hyun-Chul Lee

In the approach of the effective field theory of modified gravity, we derive the second-order action and the equation of motion for tensor perturbations on the flat isotropic cosmological background. This analysis accommodates a wide range…

High Energy Physics - Theory · Physics 2015-05-27 Antonio De Felice , Shinji Tsujikawa

Models of cosmic inflation suggest that our universe underwent an early phase of accelerated expansion, driven by the dynamics of one or more scalar fields. Inflationary models make specific, quantitative predictions for several observable…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-10 David I. Kaiser

We give an explicit relation, up to second-order terms, between scalar-field fluctuations defined on spatially-flat slices and the curvature perturbation on uniform-density slices. This expression is a necessary ingredient for calculating…

General Relativity and Quantum Cosmology · Physics 2016-05-18 Mafalda Dias , Joseph Elliston , Jonathan Frazer , David Mulryne , David Seery

We study single field inflation in noncommutative spacetime and compute two-point and three-point correlation functions for the curvature perturbation. We find that both power spectrum and bispectrum for comoving curvature perturbation are…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-20 Akhilesh Nautiyal

We study inflation in models with many interacting fields subject to randomly generated scalar potentials. We use methods from non-equilibrium random matrix theory to construct the potentials and an adaption of the 'transport method' to…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 Mafalda Dias , Jonathan Frazer , M. C. David Marsh

The transport of energetic particles in a spatially varying magnetic field is described by the focused transport equation. In the past two versions of this equation were investigated. The more commonly used standard form described a…

Solar and Stellar Astrophysics · Physics 2025-09-11 B. Klippenstein , A. Shalchi

Constraining inflationary models with high precision bispectra across broad parameter ranges is a challenging task, requiring intensive computations at all stages, first, predicting the primordial inflation bispectrum from quantum field…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-29 Bowei Zhang , E. P. S. Shellard , James R. Fergusson

Forthcoming missions probing the absolute intensity of the CMB are expected to be able to measure spectral distortions, which are deviations from its blackbody distribution. As cosmic inflation can induce spectral distortions, these…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-22 Alexander Baur , Marcos A. G. Garcia , Raul Henriquez-Ortiz , Mauricio Hernandez-Neri , Saul Ramos-Sanchez
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