BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Panos Papazoglu (Oxford)\, Urs Lang (ETH Zurich)\, Karim Adiprasit o (Hebrew University & University of Copenhagen) DTSTART:20210427T130000Z DTEND:20210427T160000Z DTSTAMP:20260710T081600Z UID:GroupTheoryENS/7 DESCRIPTION:Title: An afternoon on asymptotic dimension\nby Panos Papazoglu (Oxfor d)\, Urs Lang (ETH Zurich)\, Karim Adiprasito (Hebrew University & Univers ity of Copenhagen) as part of ENS group theory seminar\n\n\nAbstract\n15.0 0 - 15.45 Panos Papazoglu (Oxford)\n\n16.00 - 16.45 Urs Lang (ETH Zuri ch)\n\n17.15 - 18.00 Karim Adiprasito (Hebrew University & University of Copenhagen)\n\n\nPanos Papazoglu\, "Asymptotic dimension of planes" (join t with K. Fujiwara)\n\nIt is easy to see that there are Riemannian manifol ds homeomorphic to $\\mathbb R ^3$\nwith infinite asymptotic dimension. In contrast to this we showed with K. Fujiwara that\nthe asymptotic dimensio n of Riemannian planes (and planar graphs) is bounded by 3. This was\nimpr oved to 2 by Jorgensen-Lang and Bonamy-Bousquet-Esperet-Groenland-Pirot-Sc ott.\n\n\n\nUrs Lang\, "Assouad-Nagata dimension and Lipschitz extensions "\n\nIt follows from a recent result of Fujiwara-Papasoglu and a Hurewicz -type theorem due to Brodskiy-Dydak-Levin-Mitra that every planar geodesic metric space has\n\n(Assouad-)Nagata dimension at most two and hence asym ptotic dimension at most two. This can be used further to prove that every three-dimensional Hadamard manifold \n\nhas Nagata dimension three and is an absolute Lipschitz retract (joint work with Martina Jørgensen). The r ole of the Nagata dimension in Lipschitz extension problems\nwill be discu ssed further.\n\n\nKarim Adiprasito\, "l^2 cohomology and stable Lefschetz theory"\n LOCATION:https://researchseminars.org/talk/GroupTheoryENS/7/ END:VEVENT END:VCALENDAR