Peculiar velocities in the local Universe: comparison of different models and the implications for <i>H</i>0 and dark matter

ABSTRACT When measuring the value of Hubble parameter, H0, it is necessary to know recession velocity free effects peculiar velocities. In this work, we study different models in local Universe. particular, compare based on density reconstruction from galaxy redshift surveys and kernel smoothing data. The field obtained using 2M++ compilation, which compared two adaptive kernel-smoothed fields: first 6dF Fundamental Plane sample other a Tully–Fisher catalogue by combining SFI++ 2MTF. We highlight that smoothed fields should be rescaled obtain unbiased estimates. Comparing predictions these observations few test sets data, Second Amendment Supernovae catalogues, find provides better model Universe than models. impact velocities measurement H0 gravitational waves megamasers. doing so, introduce probabilistic framework marginalize over corrections along line sight. For megamasers, = 70.1 ± 2.9 km s?1 Mpc?1 field. also NGC 1052-DF2, concluding short ?13 Mpc distance not likely explanation anomalously low dark matter fraction galaxy.