Geodetic convexity and Kneser graphs

التفاصيل البيبلوغرافية
العنوان: Geodetic convexity and Kneser graphs
المؤلفون: Bedo, Marcos, Leite, João V. S., Oliveira, Rodolfo A., Protti, Fábio
سنة النشر: 2022
المجموعة: Computer Science
Mathematics
مصطلحات موضوعية: Mathematics - Combinatorics, Computer Science - Discrete Mathematics, 05C76, 52A37, 05C85
الوصف: The {\em Kneser graph} $K(2n+k,n)$, for positive integers $n$ and $k$, is the graph $G=(V,E)$ such that $V=\{S\subseteq\{1,\ldots,2n+k\} : |S|=n\}$ and there is an edge $uv\in E$ whenever $u\cap v=\emptyset$. Kneser graphs have a nice combinatorial structure, and many parameters have been determined for them, such as the diameter, the chromatic number, the independence number, and, recently, the hull number (in the context of $P_3$-convexity). However, the determination of geodetic convexity parameters in Kneser graphs still remained open. In this work, we investigate both the geodetic number and the geodetic hull number of Kneser graphs. We give upper bounds and determine the exact value of these parameters for Kneser graphs of diameter two (which form a nontrivial subfamily). We prove that the geodetic hull number of a Kneser graph of diameter two is two, except for $K(5,2)$, $K(6,2)$, and $K(8,2)$, which have geodetic hull number three. We also contribute to the knowledge on Kneser graphs by presenting a characterization of endpoints of diametral paths in $K(2n+k,n)$, used as a tool for obtaining some of the main results in this work.
Comment: 1 figure
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2203.03406
رقم الأكسشن: edsarx.2203.03406
قاعدة البيانات: arXiv