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相关论文: Testing for Features in the Primordial Power Spect…

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We investigate the cosmological perturbation theory and calculate the perturbation spectra in the warm $k$-inflation. Unlike the scalar perturbations of $k$-inflation in the cold inflationary scenario, entropy perturbations should be…

广义相对论与量子宇宙学 · 物理学 2018-04-18 Zhi-Peng Peng , Jia-Ning Yu , Xiao-Min Zhang , Jian-Yang Zhu

(Shortened abstract) While a featureless, nearly scale invariant, primordial scalar power spectrum fits the most recent CMB data rather well, certain features in the spectrum are known to lead to a better fit to the data (although, the…

宇宙学与河外天体物理 · 物理学 2015-05-30 Jerome Martin , L. Sriramkumar

Standard inflation with one scalar field produces primordial perturbations with a nearly flat ('Harrison-Zeldovich') power spectrum. Here we consider first, a double inflation spectrum, and second, a massive scalar field with an interaction…

天体物理学 · 物理学 2016-08-30 Lutz V. Semig , Volker Mueller

We calculate perturbatively the normalized spatial skewness, $S_3$, and full three-point correlation function (3PCF), $\zeta$, induced by gravitational instability of Gaussian primordial fluctuations for a biased tracer-mass distribution in…

天体物理学 · 物理学 2009-10-31 Ari Buchalter , Marc Kamionkowski

Diffusion damping of the cosmic microwave background (CMB) power spectrum results from imperfect photon-baryon coupling in the pre-recombination plasma. At redshift $5 \times 10^4 < z < 2 \times 10^6$, the plasma acquires an effective…

We calculate the curvature power spectrum sourced by spectator fields that are excited repeatedly and non-adiabatically during inflation. In the absence of detailed information of the nature of spectator field interactions, we consider an…

宇宙学与河外天体物理 · 物理学 2020-07-01 Marcos A. G. Garcia , Mustafa A. Amin , Daniel Green

Several satellite missions have uncovered a series of potential anomalies in the fluctuation spectrum of the cosmic microwave background temperature, including: (1) an unexpectedly low level of correlation at large angles, manifested via…

宇宙学与河外天体物理 · 物理学 2022-01-04 Fulvio Melia , Qingbo Ma , Jun-Jie Wei , Bo Yu

One of the characteristics of the "Matter Bounce" scenario, an alternative to cosmological inflation for producing a scale-invariant spectrum of primordial adiabatic fluctuations on large scales, is a break in the power spectrum at a…

宇宙学与河外天体物理 · 物理学 2014-11-18 Hong Li , Jun-Qing Xia , Robert Brandenberger , Xinmin Zhang

A sudden small change in the second derivative of the inflaton potential can result in a universal local feature in the spectrum of primordial perturbations generated during inflation. The exact solution describing this feature \cite{minu}…

天体物理学 · 物理学 2009-07-22 Minu Joy , Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky

The detection of a primordial stochastic gravitational wave background has the potential to reveal unprecedented insights into the early universe, and possibly into the dynamics of inflation. Generically, UV-complete inflationary models…

宇宙学与河外天体物理 · 物理学 2024-02-08 Vikas Aragam , Sonia Paban , Robert Rosati

Within the class of inflationary models, k-inflation represents the most general single field framework that can be associated with an effective quadratic action for the curvature perturbations and a varying speed of sound. The incoming…

宇宙学与河外天体物理 · 物理学 2013-09-04 Jerome Martin , Christophe Ringeval , Vincent Vennin

Using modified Richardson-Lucy algorithm we reconstruct the primordial power spectrum (PPS) from Planck Cosmic Microwave Background (CMB) temperature anisotropy data. In our analysis we use different combinations of angular power spectra…

宇宙学与河外天体物理 · 物理学 2014-12-19 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

It is commonly assumed that the stochastic background of gravitational waves on cosmological scales follows an almost scale-independent power spectrum, as generically predicted by the inflationary paradigm. However, it is not inconceivable…

宇宙学与河外天体物理 · 物理学 2022-12-14 Jan Hamann , Ameek Malhotra

Prior to recombination, Silk damping causes the dissipation of energy from acoustic waves into the monopole of the Cosmic Microwave Background (CMB), resulting in spectral distortions. These can be used to probe the primordial scalar power…

宇宙学与河外天体物理 · 物理学 2015-06-18 Sebastien Clesse , Björn Garbrecht , Yi Zhu

We show that double inflation is naturally realized in K\"ahler moduli inflation, which is caused by moduli associated with string compactification. We find that there is a small coupling between the two inflatons which leads to…

宇宙学与河外天体物理 · 物理学 2015-05-20 Masahiro Kawasaki , Koichi Miyamoto

In a variety of inflation models the motion of the inflaton may trigger the production of some non-inflaton particles during inflation, for example via parametric resonance or a phase transition. Particle production during inflation leads…

宇宙学与河外天体物理 · 物理学 2010-01-07 Neil Barnaby , Zhiqi Huang

If time-dependent disruptions from slow-roll occur during inflation, the correlation functions of the primordial curvature perturbation should have scale-dependent features, a case which is marginally supported from the cosmic microwave…

宇宙学与河外天体物理 · 物理学 2018-06-04 Jinn-Ouk Gong , Gonzalo A. Palma , Spyros Sypsas

We present constraints on neutrino masses, the primordial fluctuation spectrum from inflation, and other parameters of the $\Lambda$CDM model, using the one-dimensional Ly$\alpha$-forest power spectrum measured by Palanque-Delabrouille et…

Cosmological $\alpha$-attractors stand out as particularly compelling models to describe inflation in the very early universe, naturally meeting tight observational bounds from cosmic microwave background (CMB) experiments. We investigate…

宇宙学与河外天体物理 · 物理学 2022-06-22 Laura Iacconi , Hooshyar Assadullahi , Matteo Fasiello , David Wands

(abridged) We explore the statistical properties of non-linear cosmic structures in a flat $\Lambda$CDM cosmology in which the index of the primordial power spectrum for scalar perturbations is allowed to depend on the scale. Within the…

宇宙学与河外天体物理 · 物理学 2015-05-18 C. Fedeli , F. Finelli , L. Moscardini