English

On constrained intersection representations of graphs and digraphs

Discrete Mathematics 2025-04-28 v1 Data Structures and Algorithms Information Theory Combinatorics math.IT

Abstract

We study the problem of determining optimal directed intersection representations of DAGs in a model introduced by Kostochka, Liu, Machado, and Milenkovic [ISIT2019]: vertices are assigned color sets so that there is an arc from a vertex uu to a vertex vv if and only if their color sets have nonempty intersection and vv gets assigned strictly more colors than uu, and the goal is to minimize the total number of colors. We show that the problem is polynomially solvable in the class of triangle-free and Hamiltonian DAGs and also disclose the relationship of this problem with several other models of intersection representations of graphs and digraphs.

Keywords

Cite

@article{arxiv.2504.18365,
  title  = {On constrained intersection representations of graphs and digraphs},
  author = {Ferdinando Cicalese and Clément Dallard and Martin Milanič},
  journal= {arXiv preprint arXiv:2504.18365},
  year   = {2025}
}
R2 v1 2026-06-28T23:11:21.302Z