Nonlinear Peculiar-Velocity Analysis and PCA Avishai Dekel 1

Abstract. We allow for nonlinear effects in the likelihood analysis of peculiar velocities, and obtain, 35%-lower values for the cosmological density parameter and for the amplitude of mass-density fluctuations. The power spectrum in the linear regime is assumed to be of the flat \Lambda CDM model (h = 0:65, n = 1) with only \Omega m free. Since the likelihood is driven by the nonlinear regime, we "break " the power spectrum at kb, 0:2 (h \Gamma