Self-joinings are like convex cocompact groups with “small” critical exponents

Group Actions, Geometry and Dynamics
Event time: 
Monday, September 19, 2022 - 4:00pm
LOM 206
Hee Oh
Speaker affiliation: 
Event description: 

For a convex cocompact  Kleinian group $\Gamma <\rm{SO}(n,1)$,  Sullivan (around 1985) established a fundamental relation among the critical exponent, the bottom of the L^2-spectrum of  the hyperbolic manifold $\Gamma\backslash {\mathbb H}^n$,  the quasi-regular representation $L^2(\Gamma\backslash G)$ and the Hausdorff dimension of the limit set.  We consider a higher rank analogue of this relation. For self-joinings of convex cocompact Kleinian groups (or more generally for any Anosov subgroup of a product of rank one simple algebraic groups), we discover a surprising fact that they satisfy  a similar relation as convex cocompact groups with “small” critical exponents.

This talk is based on joint works with Dongryul Kim and Yair Minsky, and with Sam Edwards in different parts.