BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Oliver Goertsches (Philipps-Universität Marburg) DTSTART:20250917T160000Z DTEND:20250917T170000Z DTSTAMP:20260423T021416Z UID:VSGS/115 DESCRIPTION:Title: O n torus equivariant $S^4$-bundles over $S^4$ and Petrie-type Questions for GKM Manifolds\nby Oliver Goertsches (Philipps-Universität Marburg) a s part of Virtual seminar on geometry with symmetries\n\n\nAbstract\nIn GK M theory one associates to certain torus actions on closed manifolds a lab elled graph which describes the induced action on the equivariant one-skel eton. It can be regarded as a generalization of (quasi)toric theory\, reta ining only the one-skeleton of the orbit space polytope. In this talk I wi ll explain an interesting class of examples of GKM manifolds in dimension 8 with exotic behavior: it contains pairs of homotopy equivalent GKM manif olds with different first Pontryagin class\, as well as pairs of GKM actio ns on the same smooth manifold whose GKM graphs do not agree as unsigned g raphs. This is in line with previous results that show that GKM manifolds exhibit rigid behaviour only in dimensions up to 6.\n\nThis is joint work with Panagiotis Konstantis and Leopold Zoller.\n LOCATION:https://researchseminars.org/talk/VSGS/115/ END:VEVENT END:VCALENDAR