Résumé / Abstract Seminaire_IAP
« Galaxy clustering: some aspects of the halo model »

Stéphane Colombi

The halo model provides a simple but very powerful description of galaxy clustering that depends only on a few control parameters. The elementary bricks of the halo model are dark matter halos, in which luminous galaxies are distributed following simple recipes. In the most simple set up of the halo model, which gives already spectacular results, halos are spherical and the way galaxies are distributed inside them does not depend on environment, for instance on the local dark matter halo number density. I shall explain in details the fundements of the halo model and the way it is currently used, e.g. in the SDSS, to infer constraints on models of large scale structure formation. During the course of that talk, I will mention my own contributions, which concern the count-in-cells probability distribution function and its scaling properties. Starting from a simple point cluster model, I will show progressively how the subtle alchemy of the halo model acts on count-in-cells.
To illustrate my arguments or just for the sake of it, I shall show as well a few movies, in particular a travel in the largest dark matter simulation ever made.
vendredi 19 décembre 2008 - 11:00
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage