Inversion diameter and 2-edge-colored homomorphisms

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Arana, Carmen, Bellitto, Thomas, Buffière, Hector, Chuet, Quentin, Pierron, Théo, Reinald, Amadeus
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915823608659968
author Arana, Carmen
Bellitto, Thomas
Buffière, Hector
Chuet, Quentin
Pierron, Théo
Reinald, Amadeus
author_facet Arana, Carmen
Bellitto, Thomas
Buffière, Hector
Chuet, Quentin
Pierron, Théo
Reinald, Amadeus
contents In an oriented graph, the inversion of a subset of vertices X is the operation reversing the direction of every arc with both endpoints in X. Given a graph G, the inversion distance between two orientations G is the minimum number of inversions transforming one into the other. The inversion diameter diam(G) is the maximum such distance over all pairs of orientations of G. Through an equivalent formulation of inversions over 2-edge-colorings of G, we introduce the use of homomorphism-universal 2-edge-colored graphs to obtain bounds on the inversion diameter of various classes of graphs. Our first result upper bounds the inversion diameter by a linear function of the acyclic chromatic number, improving on the previous quadratic dependency. We then consider the inversion diameter of planar graphs, exhibiting a lower bound of 6, as well as new lower and upper bounds for those of a given girth, in particular settling the girth 7 case. We then show that any triangle-free graph G with maximum degree D satisfies diam(G) <= D + log D, making progress on the conjecture of Havet et al. that diam(G) <= D. Finally, we prove a general result about subdivisions: if a graph has inversion diameter k, any of its subdivisions has inversion diameter at most k + log k + 5.
format Preprint
id arxiv_https___arxiv_org_abs_2602_24171
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Inversion diameter and 2-edge-colored homomorphisms
Arana, Carmen
Bellitto, Thomas
Buffière, Hector
Chuet, Quentin
Pierron, Théo
Reinald, Amadeus
Combinatorics
Discrete Mathematics
05C10, 05C20, 05C50
In an oriented graph, the inversion of a subset of vertices X is the operation reversing the direction of every arc with both endpoints in X. Given a graph G, the inversion distance between two orientations G is the minimum number of inversions transforming one into the other. The inversion diameter diam(G) is the maximum such distance over all pairs of orientations of G. Through an equivalent formulation of inversions over 2-edge-colorings of G, we introduce the use of homomorphism-universal 2-edge-colored graphs to obtain bounds on the inversion diameter of various classes of graphs. Our first result upper bounds the inversion diameter by a linear function of the acyclic chromatic number, improving on the previous quadratic dependency. We then consider the inversion diameter of planar graphs, exhibiting a lower bound of 6, as well as new lower and upper bounds for those of a given girth, in particular settling the girth 7 case. We then show that any triangle-free graph G with maximum degree D satisfies diam(G) <= D + log D, making progress on the conjecture of Havet et al. that diam(G) <= D. Finally, we prove a general result about subdivisions: if a graph has inversion diameter k, any of its subdivisions has inversion diameter at most k + log k + 5.
title Inversion diameter and 2-edge-colored homomorphisms
topic Combinatorics
Discrete Mathematics
05C10, 05C20, 05C50
url https://arxiv.org/abs/2602.24171