High-precision Monte-Carlo modelling of galaxy distribution

Understand

We revisit the case of fast Monte-Carlo simulations of galaxy positions for a non-gaussian field.

• More precisely we address the question of generating a 3D field with a given one-point function (as a log-normal one, but not only) and some power-spectrum fixed by cosmology.
• We highlight and investigate a problem that occurs when the field is filtered and identify, for the log-normal case, a regime where it can still be used.
• However we show that the filtering is unnecessary if one takes into account aliasing effects and finely controls the discrete sampling step.