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.
R. Takahashi et al., "Simulations of Baryon Acoustic Oscillations: Likelihood Analysis of the Matter Power Spectrum," Proceedings of the 19th Workshop on General Relativity and Gravitation in Japan (2009, Tokyo, Japan), pp. 331-334, Hisaaki Shinkai Publications, Dec 2009.
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
Article - Conference proceedings
© 2009 Hisaaki Shinkai Publications, All rights reserved.
01 Dec 2009