scholarly journals Probing the primordial power spectrum with cluster number counts

2009 ◽  
Vol 79 (8) ◽  
Author(s):  
Teeraparb Chantavat ◽  
Christopher Gordon ◽  
Joseph Silk
Keyword(s):  
Power Spectrum ◽  
Cluster Number ◽  
Primordial Power Spectrum ◽  
Number Counts

scholarly journals Constraints from thermal Sunyaev-Zel’dovich cluster counts and power spectrum combined with CMB

2018 ◽  
Vol 614 ◽  
pp. A13 ◽  
Author(s):  
Laura Salvati ◽  
Marian Douspis ◽  
Nabila Aghanim
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Power Spectrum ◽  
Large Scale ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Cluster Number ◽  
Number Count ◽  
First Case ◽  
Number Counts

The thermal Sunyaev-Zel’dovich (tSZ) effect is one of the recent probes of cosmology and large-scale structures. We update constraints on cosmological parameters from galaxy clusters observed by the Planck satellite in a first attempt to combine cluster number counts and the power spectrum of hot gas; we used a new value of the optical depth and, at the same time, sampling on cosmological and scaling-relation parameters. We find that in the ΛCDM model, the addition of a tSZ power spectrum provides small improvements with respect to number counts alone, leading to the 68% c.l. constraints Ωm = 0.32  ± 0.02, σ8 = 0.76  ± 0.03, and σ8(Ωm/0.3)1/3 = 0.78  ± 0.03 and lowering the discrepancy with results for cosmic microwave background (CMB) primary anisotropies (updated with the new value of τ) to ≃1.8σ on σ8. We analysed extensions to the standard model, considering the effect of massive neutrinos and varying the equation of state parameter for dark energy. In the first case, we find that the addition of the tSZ power spectrum helps in improving cosmological constraints with respect to number count alone results, leading to the 95% upper limit ∑ mν < 1.88 eV. For the varying dark energy equation of state scenario, we find no important improvements when adding tSZ power spectrum, but still the combination of tSZ probes is able to provide constraints, producing w = −1.0 ± 0.2. In all cosmological scenarios, the mass bias to reconcile CMB and tSZ probes remains low at (1 − b) ≲ 0.67 as compared to estimates from weak lensing and X-ray mass estimate comparisons or numerical simulations.

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 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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