BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Discrete Mathematics Group - ECPv6.15.20//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-ORIGINAL-URL:https://dimag.ibs.re.kr
X-WR-CALDESC:Events for Discrete Mathematics Group
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Asia/Seoul
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:KST
DTSTART:20180101T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Asia/Seoul:20191112T163000
DTEND;TZID=Asia/Seoul:20191112T173000
DTSTAMP:20260420T184414
CREATED:20190920T115103Z
LAST-MODIFIED:20240705T204218Z
UID:1402-1573576200-1573579800@dimag.ibs.re.kr
SUMMARY:Tony Huynh\, Stable sets in graphs with bounded odd cycle packing number
DESCRIPTION:It is a classic result that the maximum weight stable set problem is efficiently solvable for bipartite graphs.  The recent bimodular algorithm of Artmann\, Weismantel and Zenklusen shows that it is also efficiently solvable for graphs without two disjoint odd cycles.  The complexity of the stable set problem for graphs without $k$ disjoint odd cycles is a long-standing open problem for all other values of $k$.  We prove that under the additional assumption that the input graph is embedded in a surface of bounded genus\, there is a polynomial-time algorithm for each fixed $k$.  Moreover\, we obtain polynomial-size extended formulations for the respective stable set polytopes. \nTo this end\, we show that 2-sided odd cycles satisfy the Erdős-Pósa property in graphs embedded in a fixed surface. This result may be of independent interest and extends a theorem of Kawarabayashi and Nakamoto asserting that odd cycles satisfy the Erdős-Pósa property in graphs embedded in a fixed orientable surface. \nEventually\, our findings allow us to reduce the original problem to the problem of finding a minimum-cost non-negative integer circulation of a certain homology class\, which we prove to be efficiently solvable in our case. \nThis is joint work with Michele Conforti\, Samuel Fiorini\, Gwenaël Joret\, and Stefan Weltge.
URL:https://dimag.ibs.re.kr/event/2019-11-12/
LOCATION:Room B232\, IBS (기초과학연구원)
CATEGORIES:Discrete Math Seminar
END:VEVENT
END:VCALENDAR