English

The Weak Version of the Graph Complement Conjecture and Partial Results for the Delta Conjecture

Combinatorics 2025-06-02 v1

Abstract

Since the transformative workshop by the American Institute of Mathematics on the minimum rank of a graph, two longstanding open problems have captivated the community interested in the minimum rank of graphs: the graph complement conjecture and the δ\delta-conjecture. In this paper, we use a classical result of Mader (1972) to establish a weak version of the graph complement conjecture for all key minimum rank parameters. In addition, again using the same result of Mader, we present some extremal resolutions of the δ\delta-conjecture. Furthermore, we incorporate the assumption of the δ\delta-conjecture and extensive work on graph degeneracy to improve the bound in the weak version of the graph complement conjecture. We conclude with a list of conjectured bounds on the positive semidefinite variant of the Colin de Verdi\`ere number.

Keywords

Cite

@article{arxiv.2505.24577,
  title  = {The Weak Version of the Graph Complement Conjecture and Partial Results for the Delta Conjecture},
  author = {Francesco Barioli and Shaun M. Fallat and Himanshu Gupta and Zhongshan Li},
  journal= {arXiv preprint arXiv:2505.24577},
  year   = {2025}
}
R2 v1 2026-07-01T02:50:36.601Z