BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Annette Karrer (McGill) DTSTART:20221004T130000Z DTEND:20221004T150000Z DTSTAMP:20260423T041009Z UID:WienGAGT/23 DESCRIPTION:Title: Contracting boundaries of right-angled Coxeter and Artin groups\nby Annette Karrer (McGill) as part of Vienna Geometry and Analysis on Groups Seminar\n\n\nAbstract\nA complete CAT(0) space has a topological space ass ociated to it called the contracting or Morse boundary. This boundary capt ures how similar the CAT(0) space is to a hyperbolic space. Charney--Sulta n proved this boundary is a quasi-isometry invariant\, i.e. it can be defi ned for CAT(0) groups. Interesting examples arise among contracting bounda ries of right-anlged Artin and Coxeter groups. \n\nThe talk will consist o f two parts. The first 45 minutes will be about the main result of my PhD project. We will study the question of how the contracting boundary of a r ight-connected Coxeter group changes when we glue certain graphs on its de fining graph. We will focus on the question of when the resulting graph co rresponds to a right-angled Coxeter group with totally disconnected contra cting boundary. \n\nAfter a short break\, we will see a second result of my PhD thesis concerning the question of what happens if we glue a path of length at least two to a defining graph of a RACG. Afterwards\, we will u se our insights to investigate contracting boundaries of certain RACGs t hat contain surprising circles. These examples are joint work with Marius Graeber\, Nir Lazarovich\, and Emily Stark. Finally\, we will transfer the ideas we saw before to RAAGs. This will result in a proof that all right- angled Artin groups have totally disconnected contracting boundaries\, rep roving a result of Charney--Cordes--Sisto.\n LOCATION:https://researchseminars.org/talk/WienGAGT/23/ END:VEVENT END:VCALENDAR