Project description
Study explores noncommutative ergodic theory’s impact on Lie group rigidity
Noncommutative ergodic theory explores the behaviour of dynamical systems through operator algebras. Recent advancements in this field have unveiled significant insights, such as a noncommutative version of Nevo-Zimmer’s structure theorem, enhancing understanding of ergodic theory, topological dynamics, unitary representation theory, and operator algebras associated with higher-rank lattices. Key achievements include a noncommutative analogue of Margulis’ factor theorem, providing strong evidence for Connes’ rigidity conjecture and highlighting interactions between discrete subgroups of semi-simple Lie groups and operator algebras. The ERC-funded NET project aims to explore character rigidity and the dynamics of positive definite functions while also developing methods to tackle Connes’ conjecture. Project results could potentially reveal new rigidity phenomena in higher-rank semi-simple Lie groups.
Objective
Noncommutative ergodic theory of higher rank lattices is a current topic that has seen several exciting developments in the last five years. Among these recent advancements, in joint work with Rmi Boutonnet (2019), we proved a noncommutative analogue of Nevo-Zimmer's structure theorem for actions of higher rank lattices on von Neumann algebras. First of all, we derived several novel applications to ergodic theory, topological dynamics, unitary representation theory and operator algebras associated with higher rank lattices. Then we obtained a noncommutative analogue of Margulis' factor theorem that provides strong evidence towards Connes' rigidity conjecture for the group von Neumann algebra of higher rank lattices. These results revealed deep and unexpected interactions between the field of discrete subgroups of semisimple Lie groups and the field of operator algebras.
In this research project, I plan to build upon these recent achievements to develop new directions in noncommutative ergodic theory of higher rank lattices. This research proposal is centered around two main interconnected themes.
Firstly, I plan to work on several problems and conjectures around the dynamics of the space of positive definite functions and character rigidity for higher rank lattices. These include the classification of characters for higher rank lattices of product type, and more general lattices with dense projections in product groups as well as stiffness results for stationary positive definite functions.
Secondly, drawing inspiration from Margulis' superrigidity theorem, I plan to tackle Connes' rigidity conjecture for higher rank lattices by developing a novel strategy combining techniques from boundary theory, C*-algebras and von Neumann algebras. These methods will lead to new rigidity phenomena for operator algebras arising from irreducible lattices in higher rank semisimple connected Lie groups.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
You need to log in or register to use this function
Programme(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Topic(s)
Funding Scheme
HORIZON-ERC - HORIZON ERC GrantsHost institution
75230 Paris
France