Adi Nusser
Dept. Physics, Israël Inst. Technology (Technion) (Haïfa, Israël)
The physics of the dark matter particles is exceedingly simple, with gravity as the only long range force acting in the dark sector.
An improvement to the standard model is offered by the introduction of a long range fifth force in the dark sector only.
Since baryonic matter is not affected by this force, the acceleration of a cosmic object depend on their dark matter content. This sometimes is referred to as violation of the equivalence principle in the dark sector.
The Sagittarius dwarf and its associated tidal stream are discussed in the context of this scenario.
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris