Geometry of homogeneous spaces & number theory



References

1. Metric spaces of non-positive curvature, Bridson-Haefliger, Springer-1991 (week 1-8)

2. Ratner Theorems on Unipotent flows, Dave Witte Morris, Chicago press (week 5-8)

3. Ergodic theory and Topological dynamics of group actions on homogeneous spaces Bekka-Mayer, LMS lecture note series 269. Cambridge Univ. Press. (week 1-8)

3. Lie groups beyond introduction, Knapp, Progress in Math. 140, Birkhauser (week 3-4, for advanced grad students)

4. Ergodic Theory with a view towards Number Theory, Einsiedler-Ward, Springer (GTM 259) (week 10-15)

5. Dynamical systems and diophantine approximation, Bugeaud, Dalbo, Drutu, eds.SMF-2009 (week 13-15)

6. Homogeneous spaces, moduli spaces and arithmetic, Einsiedler et al. (Clay Math Proceedings) AMS-2007 (week 10-15)

 


 

Syllabus

 

 

PART I : Geometry of homogeneous spaces

Week 1-2 (Sept 5-12). Basic properties of metric spaces of non-positive curvature (hyperbolic plane on Sept 5-7, more general spaces Sept 10-12)

Week 3-4 (Sept 19-28). Lie groups and Lie algebra, Cartan decomposition, Iwasawa decomposition, homogeneous spaces, etc. (SL_2 on Sept 19, SL_n on Sept 21-28)

Week 5-6 (Oct 5-12). Isometries, group actions, geodesic flow, unipotent flow. Ratner theorems I.

Week 7-8 (Oct 17-26) Boundary theory : Tits boundary, Gromov boundary, Busemann boundary, and Martin boundary. Ratner theorems II.

Week 9 (Oct. 31- Nov. 2). : Discussion session. Midterm presentation.

 

PART II : Homogeneous dynamics and number theory

Week 10-11 (Nov. 7-16). Introduction to Diophantine approximation.

Week 12 (Nov. 21-23). Quadratic forms, Oppenheim conjecture

Week 13 (Dec 28-30). Littlewood conjecture

Week 14-15 (Dec. 5-12). Survey on badly approximable sets, Hausdorff dimension, etc.

Week 15 (Dec. 12-14). Discussion session. Final presentation and/or oral exam.