Simulations of Baryon Acoustic Oscillations: Likelihood Analysis of the Matter Power Spectrum


We study the sample variance of the matter power spectrum for the standard Λ Cold Dark Matter universe. We use a total of 5000 cosmological N-body cosmological simulations to study the cosmological parameter estimations using the Fisher matrix analysis with and without including non-Gaussian errors. For the Fisher matrix analysis, we compute the derivatives of the matter power spectrum with respect to cosmological parameters using directly full nonlinear simulations. We show that the non-Gaussian errors increase the unmarginalized errors by up to a factor 5 for kmax = 0.4h/Mpc if there is only one free parameter (if other parameters are well determined by external information). On the other hand, for multi-parameter fitting, the impact of the non-Gaussian errors is significantly mitigated due to severe parameter degeneracies in the power spectrum.

Meeting Name

19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009 (2009: Nov. 30-Dec. 4, Tokyo, Japan)



Keywords and Phrases

Acoustic oscillation; Cold dark matters; Cosmological parameters; External informations; Free parameters; Likelihood analysis; Multi-parameter fitting; Nonlinear simulations, Cosmic ray measurement; Errors; Gaussian noise (electronic); Gravitation; Relativity, Power spectrum

Document Type

Article - Conference proceedings

Document Version


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© 2009 Hisaaki Shinkai Publications, All rights reserved.

Publication Date

01 Dec 2009

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