Activities This Week
Arithmetic applications of o-minimality
The definable Oka theorem Online
May 4, 10:10—12:00, 2021, online
Speaker
Eitan Sayag (BGU)
Abstract
- Coherence - classical.
- Proof of Oka - sketch of classical (via Weierstrass preparation and division, etc).
- Proof of definable Oka - sketch of steps and discussion of problematic points.
If time permits, I will report on the bourbaki text I sent during the previous lecture.
Jerusalem - Be'er Sheva Algebraic Geometry Seminar
TBA
May 5, 15:00—16:30, 2021,
BGU Probability and Ergodic Theory (PET) seminar
Infinite volume and infinite injectivity radius Online
May 6, 11:10—12:00, 2021, Online
Speaker
Tsachik Gelander (Weizmann Institute)
Abstract
We prove the following conjecture of Margulis. Let M=Λ\G/K be a locally symmetric space where G is a simple Lie group of real rank at least 2. If M has infinite volume then it admits injected contractible balls of any radius. This generalizes the celebrated normal subgroup theorem of Margulis to the context of arbitrary discrete subgroups of G and has various other applications. We prove this result by studying random walks on the space of discrete subgroups of G and analysing the possible stationary limits.
This is a joint work with Mikolaj Fraczyk.