Galaxy Environment

The environment of a galaxy is a key factor in determining the evolution of galaxies.

One key is the galaxy-halo connection; how the dark matter halo that a galaxy is in affects its evolution.

Typically this requires assuming some knowledge of the underlying dark matter distribution, and then measuring some properties of the galaxy population and constraining what the relationship could be.

This can be probed in a number of ways:

- Galaxy number counts; if the comoving number density of galaxies

- Galaxy-galaxy clustering;

- Galaxy-galaxy lensing;