Technion Mathematics Colloquium Announcement for the first of TWO colloquium talks on Monday, January 10. Title: Distribution of compact A-orbits Speaker: Manfred Einsiedler (ETH) Abstract We will discuss the distribution properties of compact A-orbits on SL(2, Z) \ SL(2, R) and SL(3, Z) \ SL(3, R) where A is the diagonal subgroup. In the former case the equdistri- bution is a result of Duke building on work of Iwaniec, and the proof is of purely number theoretic nature. In the latter case the equdistribution is joint work with E. Lindenstrauss, Ph. Michel, and A. Venkatesh, and the proof uses ergodic and number theoretic methods. We will contrast these two cases and also compare the situation with similar results e.g. for the horocycle flow. We will introduce the above spaces, recall the connection to quadratic and cubic number fields, and discuss the ergodic theorems needed. Monday,January 10 3:30 p.m. Amado 232 Light refreshments will be served at 3:00pm at the faculty lounge on the 8th floor --------------------------------------------------------- Technion Math. Net (TECHMATH) Editor: Michael Cwikel <techm@math.technion.ac.il> Announcement from: Tamar Ziegler <tamarzr@techunix.technion.ac.il>