scholarly journals Breaking the scale invariance of the primordial power spectrum in Hořava-Lifshitz cosmology

2009 ◽  
Vol 80 (6) ◽  
Author(s):  
Kazuhiro Yamamoto ◽  
Tsutomu Kobayashi ◽  
Gen Nakamura
Keyword(s):  
Power Spectrum ◽  
Scale Invariance ◽  
Primordial Power Spectrum

scholarly journals Potential reconstruction from general power spectrum in single-field inflation

2022 ◽  
Vol 2022 (01) ◽  
pp. 012
Author(s):  
Ki-Young Choi ◽  
Jinn-Ouk Gong ◽  
Su-beom Kang ◽  
Rathul Nath Raveendran
Keyword(s):  
Power Spectrum ◽  
Scale Invariance ◽  
New Method ◽  
Slow Roll ◽  
Primordial Power Spectrum ◽  
General Power ◽  
Single Field

Abstract We suggest a new method to reconstruct, within canonical single-field inflation, the inflaton potential directly from the primordial power spectrum which may deviate significantly from near scale-invariance. Our approach relies on a more generalized slow-roll approximation than the standard one, and can probe the properties of the inflaton potential reliably. We give a few examples for reconstructing potential and discuss the validity of our method.

scholarly journals Reconstruction of the primordial power spectrum by direct inversion

2010 ◽  
Vol 2010 (01) ◽  
pp. 016-016 ◽  
Author(s):  
Gavin Nicholson ◽  
Carlo R Contaldi ◽  
Paniez Paykari
Keyword(s):  
Power Spectrum ◽  
Direct Inversion ◽  
Primordial Power Spectrum

scholarly journals Scale invariance of the primordial tensor power spectrum

2017 ◽  
Vol 95 (8) ◽  
Author(s):  
Gonzalo A. Palma ◽  
Bastián Pradenas ◽  
Walter Riquelme ◽  
Spyros Sypsas
Keyword(s):  
Power Spectrum ◽  
Scale Invariance ◽  
Tensor Power

scholarly journals Constraints on primordial power spectrum from galaxy luminosity functions

2020 ◽  
Vol 102 (8) ◽  
Author(s):  
Shintaro Yoshiura ◽  
Masamune Oguri ◽  
Keitaro Takahashi ◽  
Tomo Takahashi
Keyword(s):  
Power Spectrum ◽  
Primordial Power Spectrum ◽  
Luminosity Functions

scholarly journals Primordial power spectrum and cosmology from black-box galaxy surveys

2019 ◽  
Vol 490 (3) ◽  
pp. 4237-4253 ◽  
Author(s):  
Florent Leclercq ◽  
Wolfgang Enzi ◽  
Jens Jasche ◽  
Alan Heavens
Keyword(s):  
Power Spectrum ◽  
Numerical Models ◽  
A Priori ◽  
Cosmological Parameters ◽  
Physical Structure ◽  
Black Box ◽  
Acoustic Oscillations ◽  
Galaxy Surveys ◽  
Matter Power Spectrum ◽  
Primordial Power Spectrum

ABSTRACT We propose a new, likelihood-free approach to inferring the primordial matter power spectrum and cosmological parameters from arbitrarily complex forward models of galaxy surveys where all relevant statistics can be determined from numerical simulations, i.e. black boxes. Our approach, which we call simulator expansion for likelihood-free inference (selfi), builds upon approximate Bayesian computation using a novel effective likelihood, and upon the linearization of black-box models around an expansion point. Consequently, we obtain simple ‘filter equations’ for an effective posterior of the primordial power spectrum, and a straightforward scheme for cosmological parameter inference. We demonstrate that the workload is computationally tractable, fixed a priori, and perfectly parallel. As a proof of concept, we apply our framework to a realistic synthetic galaxy survey, with a data model accounting for physical structure formation and incomplete and noisy galaxy observations. In doing so, we show that the use of non-linear numerical models allows the galaxy power spectrum to be safely fitted up to at least kmax = 0.5 h Mpc−1, outperforming state-of-the-art backward-modelling techniques by a factor of ∼5 in the number of modes used. The result is an unbiased inference of the primordial matter power spectrum across the entire range of scales considered, including a high-fidelity reconstruction of baryon acoustic oscillations. It translates into an unbiased and robust inference of cosmological parameters. Our results pave the path towards easy applications of likelihood-free simulation-based inference in cosmology. We have made our code pyselfi and our data products publicly available at http://pyselfi.florent-leclercq.eu.

scholarly journals Imprint of inhomogeneous and anisotropic primordial power spectrum on CMB polarization

2016 ◽  
Vol 460 (2) ◽  
pp. 1577-1587 ◽  
Author(s):  
Rahul Kothari ◽  
Shamik Ghosh ◽  
Pranati K. Rath ◽  
Gopal Kashyap ◽  
Pankaj Jain
Keyword(s):  
Power Spectrum ◽  
Primordial Power Spectrum ◽  
Cmb Polarization

scholarly journals Fine features in the primordial power spectrum

2011 ◽  
Vol 2011 (12) ◽  
pp. 008-008 ◽  
Author(s):  
Kohei Kumazaki ◽  
Shuichiro Yokoyama ◽  
Naoshi Sugiyama
Keyword(s):  
Power Spectrum ◽  
Primordial Power Spectrum
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