Abstract : As a new member of the LMA, I will take advantage of this seminar series to introduce myself and to present a bit of what I used to do, my background and my current projects in Marseille. I am a physicist specialized in condensed matter theory, and I am particularly interested in the strange wave dynamics that can occur in famous Bose-Einstein condensates (BECs). I will first introduce the general idea behind Bose-Einstein condensation and present the original platform on which this state of matter was first observed, namely ultra-cold atomic gases. I will also show that BECs can now be produced quite in different systems, such as exciton-polaritons that are quasi-particles made of interacting light and electron-hole pairs in semiconductor microcavities. I will discuss the high degree of control achieved in these systems through, e.g, the engineering of the particles’ dispersion relation, which leads to unusual wave dynamics.