Fractional perfect matchings in hypergraphs

Series
Combinatorics Seminar
Time
Friday, November 5, 2010 - 3:05pm for 1 hour (actually 50 minutes)
Location
Skiles 255
Speaker
Andrzej Rucinski – A. Mickiewicz University and Emory University
Organizer
Xingxing Yu
A perfect matching in a k-uniform hypergraph H=(V,E) on n vertices is a set ofn/k disjoint edges of H, whilea fractional perfect matching in H is a function w:E>[0,1] such that for each vV we have evw(e)=1. Given n3 and 3kn, let m be the smallest integer suchthat whenever the minimum vertex degree in H satisfies δ(H)m then H contains aperfect matching, and let m be defined analogously with respect to fractional perfectmatchings. Clearly, mm.We prove that for large n, mm, and suggest an approach to determine m, andconsequently m, utilizing the Farkas Lemma. This is a joint work with Vojta Rodl.