Decycling a graph by the removal of a matching: new algorithmic and structural aspects in some classes of graphs

TL;DR

This paper investigates the problem of determining whether a graph can be made acyclic by removing a matching, providing complexity results and efficient recognition algorithms for specific graph classes.

Contribution

It introduces new complexity results for Hamiltonian subcubic graphs and offers characterizations and linear-time algorithms for chordal and distance-hereditary graphs.

Findings

Matching-decyclability is NP-complete for Hamiltonian subcubic graphs with two degree-two vertices.

Chordal and distance-hereditary graphs have characterizations leading to linear-time recognition algorithms.

Deciding matching-decyclability remains NP-complete in general, but is tractable in certain classes.

Abstract

A graph $G$ is {\em matching-decyclable} if it has a matching $M$ such that $G-M$ is acyclic. Deciding whether $G$ is matching-decyclable is an NP-complete problem even if $G$ is 2-connected, planar, and subcubic. In this work we present results on matching-decyclability in the following classes: Hamiltonian subcubic graphs, chordal graphs, and distance-hereditary graphs. In Hamiltonian subcubic graphs we show that deciding matching-decyclability is NP-complete even if there are exactly two vertices of degree two. For chordal and distance-hereditary graphs, we present characterizations of matching-decyclability that lead to $O(n)$-time recognition algorithms.