BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Drupal iCal API//EN X-WR-CALNAME:Events items teaser X-WR-TIMEZONE:America/Toronto BEGIN:VTIMEZONE TZID:America/Toronto X-LIC-LOCATION:America/Toronto BEGIN:DAYLIGHT TZNAME:EDT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 DTSTART:20240310T070000 END:DAYLIGHT BEGIN:STANDARD TZNAME:EST TZOFFSETFROM:-0400 TZOFFSETTO:-0500 DTSTART:20241103T060000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT UID:68279efaca1e9 DTSTART;TZID=America/Toronto:20250211T150000 SEQUENCE:0 TRANSP:TRANSPARENT DTEND;TZID=America/Toronto:20250211T160000 URL:/combinatorics-and-optimization/events/graphs-and-m atroids-seokbeom-kim SUMMARY:Graphs and Matroids - Seokbeom Kim CLASS:PUBLIC DESCRIPTION:Summary \n\nTITLE: Structure of tournaments with a forbidden s ubtournament\n\nSPEAKER:\n Seokbeom Kim \n\nAFFILIATION:\n KAIST\n\nLOCATI ON:\n MC 5479\n\nABSTRACT: For a tournament $S$\, a tournament is $S$-free if it has no\nsubtournament isomorphic to $S$. Until now\, there have bee n only a\nsmall number of tournaments $S$ such that the complete structure of\n$S$-free tournaments is known. \n\nLet $\\triangle(1\, 2\, 2)$ be a tournament obtained from the cyclic\ntriangle by substituting two-vertex t ournaments for two of its\nvertices. In this talk\, we present a structure theorem for\n$\\triangle(1\, 2\, 2)$-free tournaments\, which was previou sly unknown.\nAs an application\, we provide tight bounds for the chromati c number as\nwell as the size of the largest transitive subtournament for such\ntournaments.\n\nThis talk is based on joint work with Taite LaGrange \, Mathieu\nRundström\, Arpan Sadhukhan\, and Sophie Spirkl.\n DTSTAMP:20250516T202426Z END:VEVENT END:VCALENDAR