English

Packing triangles in weighted graphs

Combinatorics 2015-05-26 v2

Abstract

Tuza conjectured that for every graph GG, the maximum size ν\nu of a set of edge-disjoint triangles and minimum size τ\tau of a set of edges meeting all triangles satisfy τ2ν\tau \leq 2\nu. We consider an edge-weighted version of this conjecture, which amounts to packing and covering triangles in multigraphs. Several known results about the original problem are shown to be true in this context, and some are improved. In particular, we answer a question of Krivelevich who proved that τ2ν\tau \leq 2\nu^* (where ν\nu^* is the fractional version of ν\nu), and asked if this is tight. We prove that τ2ν16ν\tau \leq 2\nu^*-\frac{1}{\sqrt{6}}\sqrt{\nu^*} and show that this bound is essentially best possible.

Keywords

Cite

@article{arxiv.1012.0372,
  title  = {Packing triangles in weighted graphs},
  author = {Guillaume Chapuy and Matt DeVos and Jessica McDonald and Bojan Mohar and Diego Scheide},
  journal= {arXiv preprint arXiv:1012.0372},
  year   = {2015}
}

Comments

v2: 20 pages, corrected version (from 2013) following referee reports

R2 v1 2026-06-21T16:52:17.564Z