Discrete and metric divisorial gonality can be different

Publication date

2022-07

Authors

van Dobben de Bruyn, Josse
Smit, HarryISNI 0000000493301792
van der Wegen, MariekeISNI 0000000492798493

Editors

Advisors

Supervisors

Document Type

Article
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License

cc_by

Abstract

This paper compares the divisorial gonality of a finite graph G to the divisorial gonality of the associated metric graph Γ(G,1) with unit lengths. We show that dgon(Γ(G,1)) is equal to the minimal divisorial gonality of all regular subdivisions of G, and we provide a class of graphs for which this number is strictly smaller than the divisorial gonality of G. This settles a conjecture of M. Baker [3, Conjecture 3.14] in the negative.

Keywords

Chip-firing game, Finite graph, Gonality, Metric graph, Theoretical Computer Science, Discrete Mathematics and Combinatorics, Computational Theory and Mathematics

Citation

van Dobben de Bruyn, J, Smit, H & van der Wegen, M 2022, 'Discrete and metric divisorial gonality can be different', Journal of Combinatorial Theory. Series A, vol. 189, 105619, pp. 1-19. https://doi.org/10.1016/j.jcta.2022.105619