Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4651341 | Discrete Mathematics | 2006 | 6 Pages |
Abstract
Lovász asked whether the following is true for each hypergraph H and natural number k:(**) if νk(H′)=k·ν*(H′)νk(H′)=k·ν*(H′) holds for each hypergraph H′H′ arising from H by multiplication of points, then νk(H)=τk(H)νk(H)=τk(H);(****) if τk(H′)=k·τ*(H′)τk(H′)=k·τ*(H′) holds for each hypergraph H′H′ arising from H by removing edges, then τk(H)=νk(H)τk(H)=νk(H).We prove and generalize assertion (**) and give a counterexample to (****).
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
A. Schrijver, P.D. Seymour,