I.F.T.

Almuerzo-Seminario

(Lunch seminar)

Jun 20th 2000, 15:00 p.m.

Dark Matter

Juan M. Usón

(US-NRAO and U. Zaragoza)

Many searches for dark matter have been conducted over the past thirty years; all of them have been unsuccessful. Microlensing is used to probe the Halo of the Galaxy towards the Magellanic Clouds; but most of the lenses are likely to be located at the Clouds themselves. In addition, the (controversial) detection of a Neutralino by the DAMA collaboration has been rejected by recent results from the CDMS experiment. It is likely that most of the baryons in the Universe are still ionized so that it is possible that there is no baryonic dark matter. Although it is likely that the dark matter in the Milky Way is in a halo of non-baryonic dark matter, it is possible that a significant fraction (most?) might be in a tenuous halo of diffuse ionized gas with a temperature of about one million degrees.

Where: Modulo C-XVI, 3rd floor, Facultad de Ciencias U.A.M., C.U. Cantoblanco, 28049-Madrid