BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:James Oxley (Louisiana State University) DTSTART:20230406T190000Z DTEND:20230406T200000Z DTSTAMP:20260423T024611Z UID:Matroids/47 DESCRIPTION:Title: Graphs\, Matroids\, Cographs and Comatroids\nby James Oxley (Louisia na State University) as part of Matroids - Combinatorics\, Algebra and Geo metry Seminar\n\nLecture held in Room 210 The Fields Institute.\n\nAbstrac t\n“If a theorem about graphs can be expressed in terms of edges and cir cuits only it probably exemplifies a more general theorem about matroids. ” These words of Bill Tutte from 1979 have had a profound influence on r esearch in matroid theory. This talk will discuss an example of recent wor k that was motivated by Tutte’s guiding principle. The class of cographs or complement- reducible graphs is the class of graphs that can be genera ted from K1 using the operations of disjoint union and complementation. We define 2-cographs to be the graphs we get by also allowing the operation of 1-sum. By analogy\, we introduce the class of binary comatroids as the class of matroids that can be generated from the empty matroid using the o perations of direct sum and taking complements inside of binary projective space. This talk will explore the properties of 2-cographs and binary com atroids. The main results characterize these classes in terms of forbidden induced minors. This is joint work with Jagdeep Singh.\n LOCATION:https://researchseminars.org/talk/Matroids/47/ END:VEVENT END:VCALENDAR