Direct signatures of the formation time of galaxies

TL;DR

This paper demonstrates that the formation time of galaxies can be directly inferred from large-scale structure data, revealing insights into galaxy formation history and bias modeling.

Contribution

It introduces a method to measure galaxy formation times using large-scale structure and extends bias expansion recursion relations to generic tracers.

Findings

Galaxy formation time influences large-scale galaxy distribution

Bias expansion recursion relations are generalized for various tracers

Large-scale structure can distinguish galaxy formation time scales

Abstract

We show that it is possible to directly measure the formation time of galaxies using large-scale structure. In particular, we show that the large-scale distribution of galaxies is sensitive to whether galaxies form over a narrow period of time before their observed times, or are formed over a time scale on the order of the age of the Universe. Along the way, we derive simple recursion relations for the perturbative terms of the most general bias expansion for the galaxy density, thus fully extending the famous dark-matter recursion relations to generic tracers.