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

200 篇论文

We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of…

天体物理学 · 物理学 2014-11-18 Rajeev Kumar Jain , Pravabati Chingangbam , Jinn-Ouk Gong , L. Sriramkumar , Tarun Souradeep

We compute the power spectrum of curvature perturbations in stochastic inflation. This combines the distribution of first crossing times through the end-of-inflation surface, which has been previously studied, with the distribution of the…

宇宙学与河外天体物理 · 物理学 2021-04-27 Kenta Ando , Vincent Vennin

Features in the primordial power spectrum have been suggested as an explanation for glitches in the angular power spectrum of temperature anisotropies measured by the WMAP satellite. However, these glitches might just as well be artifacts…

宇宙学与河外天体物理 · 物理学 2010-05-28 Jan Hamann , Arman Shafieloo , Tarun Souradeep

We investigate a model of $R^2$-gravity with a non-minimally coupled scalar field that gives rise to two-stage inflation with a break, that is, with an intermediate stage where inflation momentarily halts. We find that the power spectrum of…

宇宙学与河外天体物理 · 物理学 2024-08-06 Xinpeng Wang , Ying-li Zhang , Misao Sasaki

In the early Universe, energy stored in small-scale density perturbations is quickly dissipated by Silk-damping, a process that inevitably generates mu- and y-type spectral distortions of the cosmic microwave background (CMB). These…

宇宙学与河外天体物理 · 物理学 2015-06-04 Jens Chluba , Adrienne L. Erickcek , Ido Ben-Dayan

Features in the primordial scalar power spectrum provide a possible roadway to describe the outliers at the low multipoles in the WMAP data. Apart from the CMB angular power spectrum, these features can also alter the matter power spectrum…

宇宙学与河外天体物理 · 物理学 2013-03-04 Dhiraj Kumar Hazra

We investigate the ability of current CMB data to reliably constrain the form of the primordial power spectrum generated during inflation. We attempt to identify more exotic power spectra that yield equally good fits to the data as simple…

天体物理学 · 物理学 2009-06-23 Brian A. Powell , William H. Kinney

The effect of the initial condition of inflation on the power spectra of scalar and tensor perturbations is estimated assuming a slow-roll inflation model. By defining a more general initial state in inflation particular properties of the…

天体物理学 · 物理学 2007-10-15 Shiro Hirai , Tomoyuki Takami

We revisit the Cosmic Microwave Background (CMB) constraints on the spatial curvature of the Universe, assessing how they change when the curvature parameter and the primordial inflationary scalar spectrum are treated consistently within…

宇宙学与河外天体物理 · 物理学 2025-10-01 Enrico Specogna , Tatevik Vardanyan , William Giarè , Eleonora Di Valentino

[Abridged] A variety of model-dependent as well as model-independent approaches suggest that certain localized features in the primordial scalar power spectrum can lead to a significantly better fit to the observed anisotropies in the…

宇宙学与河外天体物理 · 物理学 2026-04-16 Alipriyo Hoory , Dhiraj Kumar Hazra , L. Sriramkumar

In the standard inflationary scenario, primordial perturbations are adiabatic. The amplitudes of most types of isocurvature perturbations are generally constrained by current data to be small. If, however, there is a baryon-density…

宇宙学与河外天体物理 · 物理学 2016-02-24 Julian B. Muñoz , Daniel Grin , Liang Dai , Marc Kamionkowski , Ely D. Kovetz

Adams et al. (1997b) have noted that according to our current understanding of the unification of fundamental interactions, there should have been phase transitions associated with spontaneous symmetry breaking {\em during} the inflationary…

天体物理学 · 物理学 2008-11-26 Jose Barriga , Enrique Gaztanaga , Mario Santos , Subir Sarkar

Measuring the deviation from scale invariance of the primordial power spectrum is a critical test of inflation. In this paper we reconstruct the shape of the primordial power spectrum of curvature perturbations from the cosmic microwave…

宇宙学与河外天体物理 · 物理学 2011-09-01 Zong-Kuan Guo , Dominik J. Schwarz , Yuan-Zhong Zhang

We constrain the primordial fluctuation spectrum P(k) by using the new data on the Cosmic Microwave Background (CMB) from the Boomerang and MAXIMA experiments. Our study is based on slow-roll inflationary models, and we consider the…

天体物理学 · 物理学 2009-10-31 S. Hannestad , S. H. Hansen , F. L. Villante

Standard CMB analysis assumes a direct deterministic mapping between the multipole probed by the CMB $\ell$ and the primordial wavenumber $k$. Since the recombination era has a finite duration, this mapping is probabilistic by construction.…

宇宙学与河外天体物理 · 物理学 2026-05-20 V. K. Oikonomou

The decrease of both the rolling speed of the inflaton and the sound speed of the curvature perturbations can amplify the curvature perturbations during inflation so as to generate a sizable amount of primordial black holes. In the…

广义相对论与量子宇宙学 · 物理学 2024-01-17 Rongrong Zhai , Hongwei Yu , Puxun Wu

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

宇宙学与河外天体物理 · 物理学 2016-06-22 Stefano Gariazzo

The angular power spectrum of the cosmic microwave background temperature anisotropy observed by WMAP has an anomalous dip at l~20 and bump at l~40. One explanation for this structure is the presence of features in the primordial curvature…

宇宙学与河外天体物理 · 物理学 2009-05-19 Michael J. Mortonson , Cora Dvorkin , Hiranya V. Peiris , Wayne Hu

The recently relased \emph{Planck} data, emphasize that the background geometry of inflation is not pure de Sitter, but from the slow variation of Hubble parameter during the inflationary era, it can be quasi-de Sitter. This motivates us to…

宇宙学与河外天体物理 · 物理学 2018-04-09 Hossein Moshafi , Ata Sojasi , Ebrahim Yusofi , Majid Mohsenzadeh

Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…

宇宙学与河外天体物理 · 物理学 2013-09-24 Raquel H. Ribeiro