BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Youngho Yoo (Georgia Institute of Technology)
DTSTART:20201210T020000Z
DTEND:20201210T030000Z
DTSTAMP:20260423T021013Z
UID:SCMSComb/22
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/SCMSComb/22/
 ">Packing A-paths and cycles with modularity constraints</a>\nby Youngho Y
 oo (Georgia Institute of Technology) as part of SCMS Combinatorics Seminar
 \n\n\nAbstract\nWe study the approximate packing-covering duality\, also k
 nown as the Erdős-Pósa property\, of various families of paths and cycle
 s with modularity constraints. Our main tool is a structure theorem for un
 directed group-labelled graphs refining the flat wall theorem of Robertson
  and Seymour\, and as a first consequence we obtain the Erdős-Pósa prope
 rty of cycles of length L mod m for any integer L and odd prime power m.\n
 This partially answers a question of Dejter and Neumann-Lara from 1987 on 
 characterizing all such integer pairs L and m. With some more work\, we al
 so prove the Erdős-Pósa property of A-paths of length 0 mod p for prime 
 p\, resolving a recent question of Bruhn and Ulmer and thereby characteriz
 ing when A-paths of length L mod m satisfy the Erdős-Pósa property. Join
 t work with Robin Thomas.\n\npw 121323\n
LOCATION:https://researchseminars.org/talk/SCMSComb/22/
END:VEVENT
END:VCALENDAR