ETHOS I

We have taken the first major step towards developing ETHOS! As I described in a previous post, we have assembled a team of theoretical physicists, cosmologists, astroparticle physicists and astrophysicists to generalize the current theory of structure formation to include additional (and allowed) non-gravitational dark matter interactions (we call this theory ETHOS).

In a first paper that we just submitted, we have taken a significant goal towards developing ETHOS by developing a mapping between the mycrophysical model of dark matter to the effective parameters that are relevant for cosmological structure formation. In this first study we have worked out how the dark matter density fluctuations grow in time during what is called the linear regime (i.e. when the fluctuations are relatively small compared to the mean).

Developing ETHOS

Given the success of our paper on SIDM and DAOs, I have decided to expand the scope of this Marie Curie project by developing a generalization of current theory of structure formation. This Effective THeory of Structure formation (ETHOS) aims at including a broad range of new dark matter interactions (including among other possibilities SIDM and DAOs) in the modelling of galaxy formation and evolution (see figure below). I came up with the acronym ETHOS inspired by one of the meanings of the Greek word: "essence", since the main goal of the theory is to explore the dark matter particle properties that are essential in galaxy formation/evolution.

This work is in collaboration with Mark Vogelsberger, Kris Sigurdson, Francis-Yan Cyr-Racine, Torsten Bringmann and Christoph Pfrommer.