摘要：Power spectrum of density variation of matter dominated era is calculated to prove that structure formation in the universe starts in the quasi-linear regime. Dimensionless power spectra for 1-halo and 2-halo for baryonic matter are calculated and compared with the 1-halo and 2-halo power spectra for dark matter. The higher values obtained for baryonic matter indicates over dense regions of baryonic matter leading to collapse to form large scale structures. The power spectrum values lead to cosmological bias values in unperturbed and perturbed universe. The obtained bias values being approaching unity indicate formation of large scale structure of galaxies starts in the quasi-linear regimes.
关键词：Cosmological bias; Large scale structure; Quasi linear regime; Power spectrum; Dark matter; Baryonic matter
