Séminaire Univers / |
| « Perturbation theory challenge in redshift space accelerated with response function approach » |
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Ken Osato |
| We study accuracy and precision with which cosmological parameters can be determined from redshift space power spectrum of matter density field up to weakly nonlinear scales using regularized perturbation theory (RegPT). We have developed the response function approach, which enables one to compute 2-loop power spectra and correction terms due to nonlinear coupling between density and velocity in a fast manner. This method is 50 times faster than the direct integration and redshift space power spectra can be computed within a few minutes. Leveraging this method, we perform cosmology challenge analysis; the cosmological parameters are inferred from power spectra measured in N-body simulations and the inferred parameters are directly compared with those used to generate initial conditions of the simulation. We have found that the cosmological parameters are correctly recovered for maximum wavenumber k_max ~< 0.2 h Mpc^-1, and modifying the damping feature improves accuracy. |
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mardi 11 janvier 2022 - 11:15 Salle du Conseil Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |