D 2023

Recognizing H-Graphs - Beyond Circular-Arc Graphs

AGAOGLU CAGIRICI, Deniz, Onur CAGIRICI, Jan DERBISZ, Tim HARTMANN, Petr HLINĚNÝ et. al.

Basic information

Original name

Recognizing H-Graphs - Beyond Circular-Arc Graphs

Authors

AGAOGLU CAGIRICI, Deniz (792 Turkey, belonging to the institution), Onur CAGIRICI (792 Turkey), Jan DERBISZ (616 Poland), Tim HARTMANN (276 Germany), Petr HLINĚNÝ (203 Czech Republic, guarantor, belonging to the institution), Jan KRATOCHVÍL (203 Czech Republic), Tomasz KRAWCZYK (616 Poland) and Peter ZEMAN (703 Slovakia)

Edition

Dagstuhl, Germany, 48th International Symposium on Mathematical Foundations of Computer Science (MFCS 2023), p. "8:1"-"8:14", 14 pp. 2023

Publisher

Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10201 Computer sciences, information science, bioinformatics

Country of publisher

Germany

Confidentiality degree

není předmětem státního či obchodního tajemství

Publication form

electronic version available online

RIV identification code

RIV/00216224:14330/23:00131122

Organization unit

Faculty of Informatics

ISBN

978-3-95977-292-1

ISSN

Keywords in English

H-graphs; Intersection Graphs; Helly Property
Změněno: 7/4/2024 23:06, RNDr. Pavel Šmerk, Ph.D.

Abstract

V originále

In 1992 Biró, Hujter and Tuza introduced, for every fixed connected graph H, the class of H-graphs, defined as the intersection graphs of connected subgraphs of some subdivision of H. Such classes of graphs are related to many known graph classes: for example, K₂-graphs coincide with interval graphs, K₃-graphs with circular-arc graphs, the union of T-graphs, where T ranges over all trees, coincides with chordal graphs. Recently, quite a lot of research has been devoted to understanding the tractability border for various computational problems, such as recognition or isomorphism testing, in classes of H-graphs for different graphs H. In this work we undertake this research topic, focusing on the recognition problem. Chaplick, Töpfer, Voborník, and Zeman showed an XP-algorithm testing whether a given graph is a T-graph, where the parameter is the size of the tree T. In particular, for every fixed tree T the recognition of T-graphs can be solved in polynomial time. Tucker showed a polynomial time algorithm recognizing K₃-graphs (circular-arc graphs). On the other hand, Chaplick et al. showed also that for every fixed graph H containing two distinct cycles sharing an edge, the recognition of H-graphs is NP-hard. The main two results of this work narrow the gap between the NP-hard and 𝖯 cases of H-graph recognition. First, we show that the recognition of H-graphs is NP-hard when H contains two distinct cycles. On the other hand, we show a polynomial-time algorithm recognizing L-graphs, where L is a graph containing a cycle and an edge attached to it (which we call lollipop graphs). Our work leaves open the recognition problems of M-graphs for every unicyclic graph M different from a cycle and a lollipop.

Links

MUNI/A/1081/2022, interní kód MU
Name: Modelování, analýza a verifikace (2023)
Investor: Masaryk University
MUNI/A/1433/2022, interní kód MU
Name: Zapojení studentů Fakulty informatiky do mezinárodní vědecké komunity 23
Investor: Masaryk University