BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251121T173055EST-9287tgxzxb@132.216.98.100 DTSTAMP:20251121T223055Z DESCRIPTION:~~In this talk we shall discuss some linkages between the PDEs of fluid dynamics and the Gauss-Codazzi-Ricci equations for isometric embe ddings of Riemannian manifolds. First\, we prove the existence of isometri c embeddings of certain negatively curved 2-dimensional surfaces into $\ma thbb{R}^3$ via a ''fluid dynamic formulation'' of the Gauss-Codazzi equati ons. The key technique is the method of compensated compactness\, previous ly used by Lax\, DiPerna\, Morawetz and others to show the existence of so lutions to hyperbolic conservation laws and transonic gas dynamics. Second \, we give global and intrinsic proofs for the weak rigidity of isometric embeddings of Riemannian/semi-Riemannian manifolds\, using the generalised compensated compactness theorems recently established in the geometric se ttings. Third\, we discuss an elementary proof for the existence of infini tely many ''wild'' solutions to the Euler equations\, previously construct ed by De Lellis\, Szekelyhidi and others via convex integrations. Our proo f relies on a direct dynamic analogue with the isometric embeddings and th e celebrated results by Nash and Gromov. The talk is based on joint works with G.-Q. Chen (Oxford)\, M. Slemrod (Wisconsin-Madison)\, Dehua Wang (Pi ttsburgh)\, and Amit Acharya (Carnegie Mellon).\n\n \n DTSTART:20170612T173000Z DTEND:20170612T183000Z LOCATION:room 1205\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Siran Li (Oxford\, CRM\, ɬÀï·¬) URL:/mathstat/channels/event/siran-li-oxford-crm-mcgil l-268492 END:VEVENT END:VCALENDAR