Modelling the asymmetry of the halo cross-correlation function with relativistic effects at quasi-linear scales

Understand

The observed galaxy distribution via galaxy redshift surveys appears distorted due to redshift-space distortions (RSD).

• While one dominant contribution to RSD comes from the Doppler effect induced by the peculiar velocity of galaxies, the relativistic effects, including the gravitational redshift effect, are recently recognized to give small but important contributions.
• Such contributions lead to an asymmetric galaxy clustering along the line of sight, and produce non-vanishing odd multipoles when cross-correlating between different biased objects.
• However, non-zero odd multipoles are also generated by the Doppler effect beyond the distant-observer approximation, known as the wide-angle effect, and at quasi-linear scales, the interplay between wide-angle and relativistic effects becomes significant.