Quotients of Hierarchically Hyperbolic Groups (HHGs)

21 Feb 2022, by ablahatherell in Sponsored events

1 – 12 August 2022

University of Bristol, UK

Supported by The Heilbronn Institute Small Grants Scheme

A workshop and mini-conference centred around the study of quotients of hierarchically hyperbolic groups (HHGs). Hierarchical hyperbolicity is a form of non-positive curvature devised by Behrstock, Hagen, and Sisto, encompassing many important classes of groups in geometric group theory, such as mapping class groups, special groups in the sense of Haglund–Wise, and most fundamental groups of 3–manifolds. It is typically quite difficult to obtain results about quotients of groups in any significant generality, so there is a great deal of interest in progress in this area.

Behrstock, Hagen, Martin, and Sisto’s paper has laid the groundwork for more general results about quotients of HHGs, however there are still several difficult pieces missing from the puzzle. We have been working on a joint project during the past year, with the aim of filling in the pieces required to prove Behrstock–Hagen–Martin–Sisto’s results in their full generality.

6 August 2022

Mini-Conference: More information on the conference website


Daniel Berlyne (Bristol)


Carolyn Abbott (Brandeis)
Jason Behrstock (CUNY)
Daniel Berlyne (Bristol)
Mark Hagen (Bristol)
Alexandre Martin (Heriot-Watt)
Thomas Ng (Technion, Israel)
Alexander Rasmussen (Utah)
Alessandro Sisto (Heriot-Watt)