##### Department of Mathematics,

University of California San Diego

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### Math 243 - Functional Analysis Seminar

## Rolando de Santiago

#### UCLA

## $L^2$ Betti numbers and s-malleable deformations

##### Abstract:

A major theme in the study of von Neumann algebras is to investigate which structural aspects of the group extend to its von Neumann algebra. I present recent progress made by Dan Hoff, Ben Hayes, Thomas Sinclair and myself in the case where the group has positive first $L^2$ Betti number. I will also expand on our analysis of s-malleable deformations and their relation to cocylces which forms the foundation of our work.

Host: Adrian Ioana

### April 9, 2019

### 11:00 AM

### AP&M 6402

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