English

Proof of the Kalai-Meshulam conjecture

Combinatorics 2018-10-02 v1

Abstract

Let GG be a graph, and let fGf_G be the sum of (1)A(-1)^{|A|}, over all stable sets AA. If GG is a cycle with length divisible by three, then fG=±2f_G= \pm 2. Motivated by topological considerations, G. Kalai and R. Meshulam made the conjecture that,if no induced cycle of a graph GG has length divisible by three, then fG1|f_G|\le 1. We prove this conjecture.

Keywords

Cite

@article{arxiv.1810.00065,
  title  = {Proof of the Kalai-Meshulam conjecture},
  author = {Maria Chudnovsky and Alex Scott and Paul Seymour and Sophie Spirkl},
  journal= {arXiv preprint arXiv:1810.00065},
  year   = {2018}
}