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Related papers: On Loops in Inflation

200 papers

We propose one way to regularize the fluctuations generated during inflation, whose infrared (IR) corrections diverge logarithmically. In the case of a single field inflation model, recently, we proposed one solution to the IR divergence…

High Energy Physics - Theory · Physics 2010-02-02 Yuko Urakawa , Takahiro Tanaka

We calculate 1-loop corrections to the Schwinger-Keldysh propagators of Standard-Model-like fields of spin-0, 1/2, and 1, with all renormalizable interactions during inflation. We pay special attention to the late-time divergences of loop…

High Energy Physics - Theory · Physics 2016-08-16 Xingang Chen , Yi Wang , Zhong-Zhi Xianyu

We first derive the primordial power spectra, spectral indices and runnings of both scalar and tensor perturbations of a flat inflationary universe to the second-order approximations of the slow-roll parameters, in the framework of loop…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Tao Zhu , Anzhong Wang , Klaus Kirsten , Gerald Cleaver , Qin Sheng , Qiang Wu

In this paper, we prove that the superhorizon conservation of the curvature perturbation zeta in single-field inflation holds as an operator statement. This implies that all zeta-correlators are time independent at all orders in the loop…

High Energy Physics - Theory · Physics 2015-06-11 Valentin Assassi , Daniel Baumann , Daniel Green

Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…

High Energy Physics - Theory · Physics 2008-11-26 Lev Kofman , Shinji Mukohyama

We describe a simple way of incorporating fluctuations of the Hubble scale during the horizon exit of scalar perturbations into the delta N formalism. The dominant effect comes from the dependence of the Hubble scale on low-frequency modes…

High Energy Physics - Theory · Physics 2010-08-12 Christian T. Byrnes , Mischa Gerstenlauer , Arthur Hebecker , Sami Nurmi , Gianmassimo Tasinato

Loop quantum cosmology provides an efficient framework to study the evolution of the Universe beyond the classical Big Bang paradigm. Because of holonomy corrections, the singularity is replaced by a "bounce". The dynamics of the background…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Jakub Mielczarek , Thomas Cailleteau , Julien Grain , Aurelien Barrau

We study the stochastic formalism of inflation beyond the usual slow-roll approximation. We verify that the assumptions on which the stochastic formalism relies still hold even far from the slow-roll attractor. This includes demonstrating…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-05 Chris Pattison , Vincent Vennin , Hooshyar Assadullahi , David Wands

We analyze the consequences of different evolutions of the Hubble parameter on the spectrum of scalar inflationary perturbations. The analysis is restricted to inflationary phases described by a transient evolution, when uncommon features…

General Relativity and Quantum Cosmology · Physics 2023-04-12 Leonardo Chataignier , Alexander Yu. Kamenshchik , Alessandro Tronconi , Giovanni Venturi

We investigate the chaotic inflationary model using the two-loop effective potential of a self-interacting scalar field theory in curved spacetime. We use the potential which contains a non-minimal scalar curvature coupling and a quartic…

High Energy Physics - Phenomenology · Physics 2015-05-20 Tomohiro Inagaki , Ryota Nakanishi , Sergei D. Odintsov

We study leading order perturbative corrections to the two point correlation function of the scalar field describing the curvature perturbation in a slow-roll inflationary background, paying particular attention to the contribution of…

High Energy Physics - Theory · Physics 2015-06-03 Wei Xue , Xian Gao , Robert Brandenberger

It is well known that the correlation functions of a scalar field in a quasi-de Sitter space exhibit at the loop level cumulative infra-red effects proportional to the total number of e-foldings of inflation. Using the in-in formalism, we…

High Energy Physics - Phenomenology · Physics 2008-11-26 Antonio Riotto , Martin S. Sloth

We extend the WKB method for the computation of cosmological perturbations during inflation beyond leading order and provide the power spectra of scalar and tensor perturbations to second order in the slow-roll parameters. Our method does…

General Relativity and Quantum Cosmology · Physics 2009-11-11 R. Casadio , F. Finelli , M. Luzzi , G. Venturi

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 study cosmological perturbations in two-field inflation, allowing for non-standard kinetic terms. We calculate analytically the spectra of curvature and isocurvature modes at Hubble crossing, up to first order in the slow-roll…

High Energy Physics - Theory · Physics 2009-11-13 Z. Lalak , D. Langlois , S. Pokorski , K. Turzynski

The prediction of a phase of inflation whose number of e-folds is constrained is an important feature of loop quantum cosmology. This work aims at giving some elementary clarifications on the role of the different hypotheses leading to this…

General Relativity and Quantum Cosmology · Physics 2017-07-05 Boris Bolliet , Aurélien Barrau , Killian Martineau , Flora Moulin

We develop a procedure for re-summing the large logarithms induced in gravity by loops of inflationary scalars. We first show how the scalar can be integrated out of the field equations in the presence of constant graviton field. We then…

General Relativity and Quantum Cosmology · Physics 2024-10-10 S. P. Miao , N. C. Tsamis , R. P. Woodard

The dynamics of quantum fields during cosmic inflation can be probed via their late-time boundary correlators. The analytic structure of these boundary correlators contains rich physical information of bulk dynamics, and is also closely…

High Energy Physics - Theory · Physics 2023-08-30 Zhehan Qin , Zhong-Zhi Xianyu

In this paper, we discuss the inflationary magnetogenesis scenario, in which the coupling function is introduced to break the conformal invariance of electromagnetic action. Unlike in conventional models, we deduce the Maxwell's equations…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Y. Li , L. Y. Zhang

Using the fact that we only observe those modes which exit the Hubble horizon during inflation, one can calculate the entanglement entropy of such long-wavelength perturbations by tracing out unobservable sub-Hubble fluctuations they are…

High Energy Physics - Theory · Physics 2022-06-14 Suddhasattwa Brahma
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