This talk will be streamed live at https://huji.cloud.panopto.eu/Panopto/Pages/Viewer.aspx?id=5f8b2e8e-7361...
After the talk the recording can be found at the same link.
Abstract:
Following Gromov's seminal work on negatively curved groups and spaces in
the mid 80s, there have been repeated attempts to find suitable
generalizations that will lead to generalizations of the techniques and
the results that were obtained in the presence of negative curvature.
Most of these attempts were not sucessful, at least not so far. In the
last decade Behrstock, Hagen and Sisto axiomatized the hierarchical
structure of the mapping class groups of surfaces, that was defined
and studied in a seminal work of Masur and Minsky.
Although the definition of these hierarchically hyperbolic spaces is
rather technical, and at first seems special, there are quite a few
examples for such spaces, that are rather far from the mapping class
groups.
I intend to explain the structure of these spaces, and some of the tools
that enable one to work with them, that include acylindrical
actions, and projection complexes and quasi-trees of metric spaces that
were constructed by Bestvina, Bromberg and Fujiwara.