BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250918T094704EDT-0687ucpVVp@132.216.98.100 DTSTAMP:20250918T134704Z DESCRIPTION:Title:  Dilatations of pseudo-Anosov maps.\n\nAbstract: A pseud o-Anosov map is a surface homeomorphism that acts with similar dynamics as a hyperbolic element of SL2R on R2. A classical result of Nielsen and Thu rston shows that these are surprisingly prevalent among mapping classes of surfaces. The dilatation of a pseudo-Anosov map is a measure of the compl exity of its dynamics. It is another classical result that the set of dila tations among all pseudo-Anosov maps defined on a fixed surface has a mini mum element. This minimum dilatation can be thought of as the smallest amo unt of mixing one can perform on the surface while still doing something t opologically interesting. The minimum dilatation problem asks for this min imum value. In this talk\, we will start by providing some background for pseudo-Anosov maps\, in particular explaining how the theory can be viewed from the perspective of outer automorphisms of surface groups. We will th en present some recent work on the minimum dilatation problem with Eriko H ironaka\, which shows a sharp lower bound for dilatations of fully-punctur ed pseudo-Anosov maps with at least two puncture orbits.\n DTSTART:20230920T190000Z DTEND:20230920T200000Z LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Chi Cheuk Tsang (Université du Québec à Montréal) URL:/mathstat/channels/event/chi-cheuk-tsang-universit e-du-quebec-montreal-351009 END:VEVENT END:VCALENDAR