タイトル（掲載誌）Monthly Notices of the Royal Astronomical Society
一般注記We formulate a perturbative approximation to gravitational instability, based on Lagrangian hydrodynamics in Newtonian cosmology. We take account of the `pressure' effect of a fluid, which is kinematically caused by velocity dispersion, to aim the hydrodynamical description beyond shell crossing. Master equations in the Lagrangian description are derived and solved perturbatively up to second order. Then, as an illustration, power spectra of density fluctuations are computed in a one-dimensional model from the Lagrangian approximations and Eulerian linear perturbation theory for comparison. We find that the results by the Lagrangian approximations are different from those by the Eulerian theory in the weakly nonlinear regime at scales smaller than the Jeans length. We also show the validity of the perturbative Lagrangian approximations by consulting the difference between the first-order and second-order approximations.
一次資料へのリンクURLhttps://u-fukui.repo.nii.ac.jp/?action=repository_action_common_download&item_id=21828&item_no=1&attribute_id=22&file_no=1
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）