BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Türkü Özlüm Çelik (Max Planck Institute of Molecular Cell Bio logy and Genetics) DTSTART:20251024T124000Z DTEND:20251024T134000Z DTSTAMP:20260423T021253Z UID:OBAGS/70 DESCRIPTION:Title: I nteraction Networks via Grassmannians\nby Türkü Özlüm Çelik (Max Planck Institute of Molecular Cell Biology and Genetics) as part of ODTU-B ilkent Algebraic Geometry Seminars\n\n\nAbstract\nWhen can a network of mu tually reinforcing N components remain stable? To approach such questions\ , we describe the interactions through generalized Lotka–Volterra equati ons—a broad class of dynamical systems modeling how components influence one another over time. This formulation leads to a family of semi-algebra ic sets determined by the sign pattern of the parameters. These sets encod e positivity conditions defining regions of potential coexistence\, with p olynomial degrees growing exponentially in N. Embedding the parameter spac e into the real Grassmannian Gr(N\,2N) transforms these conditions into si gn relations governed by the Grassmann–Plücker equations and oriented m atroids. This geometric reformulation yields a realization problem through which we detect impossible interaction networks and study the algebraic s tructure underlying stability. If time permits\, we will also touch on how these structures connect to algebraic curves. This talk is based on our r ecent work arXiv:2509.00165.\n LOCATION:https://researchseminars.org/talk/OBAGS/70/ END:VEVENT END:VCALENDAR