On the Complexity of Vertex-Splitting Into an Interval Graph

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Abu-Khzam, Faisal N., Chakraborty, Dipayan, Isenmann, Lucas, Oijid, Nacim
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866910011673804800
author Abu-Khzam, Faisal N.
Chakraborty, Dipayan
Isenmann, Lucas
Oijid, Nacim
author_facet Abu-Khzam, Faisal N.
Chakraborty, Dipayan
Isenmann, Lucas
Oijid, Nacim
contents Vertex splitting is a graph modification operation in which a vertex is replaced by multiple vertices such that the union of their neighborhoods equals the neighborhood of the original vertex. We introduce and study vertex splitting as a graph modification operation for transforming graphs into interval graphs. Given a graph $G$ and an integer $k$, we consider the problem of deciding whether $G$ can be transformed into an interval graph using at most $k$ vertex splits. We prove that this problem is NP-hard, even when the input is restricted to subcubic planar bipartite graphs. We further observe that vertex splitting differs fundamentally from vertex and edge deletions as graph modification operations when the objective is to obtain a chordal graph, even for graphs with maximum independent set size at most two. On the positive side, we give a polynomial-time algorithm for transforming, via a minimum number of vertex splits, a given graph into a disjoint union of paths, and that splitting triangle free graphs into unit interval graphs is also solvable in polynomial time.
format Preprint
id arxiv_https___arxiv_org_abs_2602_04628
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle On the Complexity of Vertex-Splitting Into an Interval Graph
Abu-Khzam, Faisal N.
Chakraborty, Dipayan
Isenmann, Lucas
Oijid, Nacim
Computational Complexity
Vertex splitting is a graph modification operation in which a vertex is replaced by multiple vertices such that the union of their neighborhoods equals the neighborhood of the original vertex. We introduce and study vertex splitting as a graph modification operation for transforming graphs into interval graphs. Given a graph $G$ and an integer $k$, we consider the problem of deciding whether $G$ can be transformed into an interval graph using at most $k$ vertex splits. We prove that this problem is NP-hard, even when the input is restricted to subcubic planar bipartite graphs. We further observe that vertex splitting differs fundamentally from vertex and edge deletions as graph modification operations when the objective is to obtain a chordal graph, even for graphs with maximum independent set size at most two. On the positive side, we give a polynomial-time algorithm for transforming, via a minimum number of vertex splits, a given graph into a disjoint union of paths, and that splitting triangle free graphs into unit interval graphs is also solvable in polynomial time.
title On the Complexity of Vertex-Splitting Into an Interval Graph
topic Computational Complexity
url https://arxiv.org/abs/2602.04628