Groups and Geometry in the South East
This is a series of meetings, with the aim of bringing together the geometric group theorists in the South East of England. The meetings are sponsored by mathematicians from the Universities of London, Oxford and Southampton, and organised by Martin Bridson and Henry Wilton. We have been awarded LMS Scheme 3 funding.
In 2013-14, the meetings will be as follows:
- 25 October 2013, UCL
- 6 December 2013, Southampton
- 21 February 2014, Warwick
- 9 May 2013, Oxford
Here are some details of our next meeting.
Friday 21st February, 2014
4pm Hyperbolic groups, Cannon-Thurston maps, and hydra
Tim Riley (Cornell)
Groups are Gromov-hyperbolic when all geodesic triangles in their Cayley graphs are close to being tripods. Despite being tree-like in this manner, they can harbour extreme wildness in their subgroups. I will describe examples stemming from a re-imagining of Hercules' battle with the hydra, where wildness is found in properties of "Cannon-Thurston maps" between boundaries. Also, I will give examples where this map between boundaries fails to be defined.