Cosmic Flows: Review of Recent Developments

TL;DR

This review summarizes recent advances in cosmic flow data analysis, highlighting improved measurements of bulk flows, galaxy peculiar velocities, and matter power spectra, which help resolve previous discrepancies in cosmological interpretations.

Contribution

The paper provides a comprehensive overview of recent developments in cosmic flow analysis, emphasizing the resolution of past inconsistencies in data interpretation.

Findings

Bulk flow measurements are consistent on smaller scales.

Peculiar velocity catalogs now align better with redshift data.

Discrepancies remain mainly on scales larger than 100 h^{-1} Mpc.

Abstract

I review the recent developments in the analysis of cosmic flow data, in particular, latest results of bulk flow measurements, comparison between redshift and peculiar velocity catalogs with emphasis on the measured value of the $\beta (=\Omega_m^{0.6}/b)$ parameter, and matter power spectrum estimates from galaxy peculiar velocity catalogs. Based on these developments, one can argue that most of the previous discrepancies in the interpretation of cosmic flow data, {\it maybe} with the exception of bulk flow measurements on scales $\gsim 100 h{^{-1}}{\rm Mpc}$, have either been resolved or fairly understood.