Modified Newtonian Dynamics: where does it work, and where does it not? -- Benoit Famaey -- Université Libre de Bruxelles

jeudi 26 mars 2009, 15:00 → 16:00 Europe/Paris

I will review the evidence for a one-to-one analytic relation between the inferred gravity of dark matter at any radius and the enclosed baryonic mass in galaxies, a relation summarized by Milgrom's law of modified Newtonian dynamics (MOND). However, present-day covariant versions of MOND usually require some additional fields contributing to the geometry, as well as an additional hot dark matter component to explain cluster dynamics. I will notably show how the gravitational lensing map of the bullet cluster constrains this hot dark matter component. I will finally suggest that dark matter could at the same time exist and be the source of MOND-like phenomenology in galaxies, by assuming a canonical action for dark matter, but also adding an interaction term between baryonic matter, gravity, and dark matter, such that standard matter effectively obeys the MOND field equation in galaxies.

Slides Famaey_MOND.pdf