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相关论文: Large curvature perturbations near horizon crossin…

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How much does the curvature perturbation change after it leaves the horizon, and when should one evaluate the power spectrum? To answer these questions we study single field inflation models numerically, and compare the evolution of…

宇宙学与河外天体物理 · 物理学 2013-02-26 Ellie Nalson , Adam J. Christopherson , Ian Huston , Karim A. Malik

The latest results from PLANCK impose strong constraints on features in the spectrum of the curvature perturbations from inflation. We analyse the possibility of particle production induced by sharp turns of the trajectory in field space in…

宇宙学与河外天体物理 · 物理学 2015-06-18 Maciej Konieczka , Raquel H. Ribeiro , Krzysztof Turzynski

We study the amplitude and spectral tilt of density perturbations in the simplest hybrid inflation models. We give an exact expression for the amplitude of quantum fluctuations on all scales in the limit where we can neglect the…

天体物理学 · 物理学 2009-06-19 Juan Garcia-Bellido , David Wands

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…

宇宙学与河外天体物理 · 物理学 2015-06-16 Nicola Bartolo , Dario Cannone , Sabino Matarrese

Fundamental formulae representing the density perturbation spectrums generated in inflationary scenarios are rigorously proved. Quantum fluctuations as initial conditions for structure generation in some inflationary era can be calculated…

天体物理学 · 物理学 2008-11-26 J. Hwang

We derive the power spectrum of primordial quantum fluctuations in an inflationary universe for curvature parameter ${\mathcal K}=1$. This is achieved through a Born--Oppenheimer type of approximation scheme from the Wheeler--DeWitt…

广义相对论与量子宇宙学 · 物理学 2022-04-05 Claus Kiefer , Tatevik Vardanyan

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…

宇宙学与河外天体物理 · 物理学 2024-04-22 Alexander Baur , Marcos A. G. Garcia , Raul Henriquez-Ortiz , Mauricio Hernandez-Neri , Saul Ramos-Sanchez

We derive general analytic formulae for the power spectrum and spectral index of the curvature perturbation produced during inflation driven by a multi-component inflaton field, up to the second order in the slow-roll approximation. We do…

天体物理学 · 物理学 2009-10-28 Takahiro T. Nakamura , Ewan D. Stewart

We study the two-field warm inflation models with a double quadratic potential and a linear temperature dependent dissipative coefficient. We derived the evolution equation of all kinds of perturbations without assuming slow-roll…

广义相对论与量子宇宙学 · 物理学 2019-05-23 Yang-yang Wang , Xiao-Min Zhang , Jian-Yang Zhu

Inflection point inflation generically includes a deviation from slow-roll when the inflaton approaches the inflection point. Such deviations are shown to be generated by transitions between singular trajectories. The effects on the power…

高能物理 - 理论 · 物理学 2013-07-22 Sean Downes , Bhaskar Dutta

We study an inflationary model driven by a single minimally coupled standard kinetic term scalar field with a step in its mass modeled by an Heaviside step function. We present an analytical approximation for the mode function of the…

宇宙学与河外天体物理 · 物理学 2012-09-04 Frederico Arroja , Antonio Enea Romano , Misao Sasaki

In this paper, we have studied the spectrum of curvature perturbation of multi-field inflation with general small-field potential. We assume that the isocurvature perturbation may be neglected, and by using the Sasaki-Stewart formalism, we…

天体物理学 · 物理学 2009-06-23 Iftikhar Ahmad , Yun-Song Piao , Cong-Feng Qiao

The large enhancement of the primordial power spectrum of the curvature perturbation can seed the formation of primordial black hole, that can play as a dark matter component in the Universe. In multi-filed inflation models, the curved…

宇宙学与河外天体物理 · 物理学 2021-07-05 Ki-Young Choi , Su-beom Kang , Rathul Nath Raveendran

We study models of inflation with two scalar fields and non-canonical kinetic terms, focusing on the case in which the curvature and isocurvature perturbations are strongly coupled to each other. In the regime where a heavy mode can be…

高能物理 - 理论 · 物理学 2011-03-10 Sera Cremonini , Zygmunt Lalak , Krzysztof Turzynski

Power suppression of the cosmic microwave background on the largest observable scales could provide valuable clues about the particle physics underlying inflation. Here we consider the prospect of power suppression in the context of the…

宇宙学与河外天体物理 · 物理学 2015-10-01 Jose J. Blanco-Pillado , Mafalda Dias , Jonathan Frazer , Kepa Sousa

We estimate large-scale curvature perturbations from isocurvature fluctuations in the waterfall field during hybrid inflation, in addition to the usual inflaton field perturbations. The tachyonic instability at the end of inflation leads to…

宇宙学与河外天体物理 · 物理学 2015-03-17 José Fonseca , Misao Sasaki , David Wands

We study non-linear contributions to the power spectrum of the curvature perturbation on super-horizon scales, produced during slow-roll inflation driven by a canonical single scalar field. We find that on large scales the linear power…

宇宙学与河外天体物理 · 物理学 2015-05-20 Jinn-Ouk Gong , Hyerim Noh , Jai-chan Hwang

We consider small-field models which invoke the usual framework for the effective field theory, and large-field models which go beyond that. Present and future possibilities for discriminating between the models are assessed, on the…

天体物理学 · 物理学 2015-06-24 Laila Alabidi , David Lyth

We argue that in models of inflation with two scalar fields and non-canonical kinetic terms there is a possibility of obtaining a red tilt of the power spectrum of curvature perturbations from noncanonicality-induced interactions between…

高能物理 - 理论 · 物理学 2015-03-17 Sera Cremonini , Zygmunt Lalak , Krzysztof Turzynski

The impact of particle production during inflation on the primordial curvature perturbation spectrum is investigated both analytically and numerically. We obtain an oscillatory behavior on small scales, while on large scales the spectrum is…

广义相对论与量子宇宙学 · 物理学 2009-02-23 Antonio Enea Romano , Misao Sasaki