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We develop a systematic framework to compute the primordial power spectrum up to next-to-next-to-next to leading order (N3LO) in the Hubble-flow parameters for a large class of effective theories of inflation. We assume that the quadratic…

General Relativity and Quantum Cosmology · Physics 2024-11-18 Eugenio Bianchi , Mauricio Gamonal

Non-Gaussianities of the primordial density perturbations have emerged as a very powerful possible signal to test the dynamics that drove the period of inflation. While in general the most sensitive observable is the three-point function in…

High Energy Physics - Theory · Physics 2011-01-17 Leonardo Senatore , Matias Zaldarriaga

An inflationary brane model driven by a bulk inflaton with exponential potential is proposed. We find a family of exact solutions that describe power-law inflation on the brane. These solutions enable us to derive exact solutions for metric…

High Energy Physics - Theory · Physics 2009-11-10 Kazuya Koyama , Keitaro Takahashi

We present a generic inference method for inflation models from observational data by the usage of higher-order statistics of the curvature perturbation on uniform density hypersurfaces. This method is based on the calculation of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-25 Sebastian Dorn , Erandy Ramirez , Kerstin E. Kunze , Stefan Hofmann , Torsten A. Enßlin

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

We show that the prediction for the primordial tensor power spectrum cannot be modified at leading order in derivatives. Indeed, one can always set to unity the speed of propagation of gravitational waves during inflation by a suitable…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Paolo Creminelli , Jérôme Gleyzes , Jorge Noreña , Filippo Vernizzi

We provide a derivation from first principles of the primordial bispectrum of scalar perturbations produced during inflation driven by a canonically normalized scalar field whose potential exhibits small sinusoidal modulations. A potential…

High Energy Physics - Theory · Physics 2015-05-18 Raphael Flauger , Enrico Pajer

The scalar and tensor fluctuations generated during inflation can be correlated, if arising from the same underlying mechanism. In this paper we investigate such correlation in the model of axion inflation, where the rolling inflaton…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-08 Sofia P. Corbà , Lorenzo Sorbo

We prove an exact relation between the tensor and the scalar primordial power spectra generated during inflation. Such a mapping considerably simplifies the derivation of any power spectra as they can be obtained from the study of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-04 Jose Beltran Jimenez , Marcello Musso , Christophe Ringeval

The recently proposed model of 'solid inflation' features a peculiar three-point function for scalar perturbations with an anisotropic, purely quadrupolar, squeezed limit. We confirm this result as well as the overall amplitude of the three…

High Energy Physics - Theory · Physics 2014-09-10 Solomon Endlich , Bart Horn , Alberto Nicolis , Junpu Wang

We calculate the primordial trispectrum of curvature perturbation in quasi-single field inflation, with general sound speeds for both the inflaton and the massive scalar. Special attention is paid to various soft limits of the trispectrum,…

High Energy Physics - Theory · Physics 2018-05-22 Xingang Chen , Wan Zhen Chua , Yuxun Guo , Yi Wang , Zhong-Zhi Xianyu , Tianyou Xie

The time evolution of primordial fluctuations conceals a wealth of insights into the high-energy physics at play during the earliest moments of our Universe, which is ultimately encoded in late-time spatial correlation functions. However,…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-12 Lucas Pinol , Sébastien Renaux-Petel , Denis Werth

We describe models of single-field inflation with small and sharp step features in the potential (and sound speed) of the inflaton field, in the context of the Effective Field Theory of Inflation. This approach allows us to study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nicola Bartolo , Dario Cannone , Sabino Matarrese

We perform the analysis of the trispectrum of curvature perturbations generated by the interactions characterizing a general theory of single-field inflation obtained by effective field theory methods. We find that curvature-generated…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Nicola Bartolo , Matteo Fasiello , Sabino Matarrese , Antonio Riotto

Inflationary scenarios in string theory often involve a large number of light scalar fields, whose presence can enrich the post-inflationary evolution of primordial fluctuations generated during the inflationary epoch. We provide a simple…

High Energy Physics - Theory · Physics 2010-08-18 C. P. Burgess , M. Cicoli , M. Gomez-Reino , F. Quevedo , G. Tasinato , I. Zavala

Inflationary predictions based on the linear theory of cosmological perturbations are related to the two point function of a (second quantized) real scalar free field during the accelerated stage. Such a two point function is finite, in…

High Energy Physics - Theory · Physics 2008-11-26 F. Finelli , G. Marozzi , G. P. Vacca , G. Venturi

Inflationary gravitational waves, behaving as additional radiation in the Early Universe, can increase the effective number of relativistic species ($N_{\rm eff}$) by a further correction that depends on the integrated energy-density in…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-09 William Giarè , Matteo Forconi , Eleonora Di Valentino , Alessandro Melchiorri

Motivated by the aim of producing significant number of primordial black holes, over the past few years, there has been a considerable interest in examining models of inflation involving a single, canonical field, that permit a brief period…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-03 Sagarika Tripathy , Debika Chowdhury , H. V. Ragavendra , L. Sriramkumar

Large turns in multifield inflation can lead to a very rich phenomenology, but are difficult to realise in supergravity, and typically require large field space curvatures. In this work, we present a mechanism to realise multiple sharp…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-24 Sukannya Bhattacharya , Ivonne Zavala

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…

Astrophysics · Physics 2009-11-10 F. J. Cao , H. J. de Vega , N. G. Sanchez