Mutual-visibility problems on graphs of diameter two

التفاصيل البيبلوغرافية
العنوان: Mutual-visibility problems on graphs of diameter two
المؤلفون: Cicerone, Serafino, Di Stefano, Gabriele, Klavžar, Sandi, Yero, Ismael G.
سنة النشر: 2024
المجموعة: Computer Science
Mathematics
مصطلحات موضوعية: Mathematics - Combinatorics, Computer Science - Discrete Mathematics, 5C12, 05C38, 05C69, 05C76
الوصف: The mutual-visibility problem in a graph $G$ asks for the cardinality of a largest set of vertices $S\subseteq V(G)$ so that for any two vertices $x,y\in S$ there is a shortest $x,y$-path $P$ so that all internal vertices of $P$ are not in $S$. This is also said as $x,y$ are visible with respect to $S$, or $S$-visible for short. Variations of this problem are known, based on the extension of the visibility property of vertices that are in and/or outside $S$. Such variations are called total, outer and dual mutual-visibility problems. This work is focused on studying the corresponding four visibility parameters in graphs of diameter two, throughout showing bounds and/or closed formulae for these parameters. The mutual-visibility problem in the Cartesian product of two complete graphs is equivalent to (an instance of) the celebrated Zarankievicz's problem. Here we study the dual and outer mutual-visibility problem for the Cartesian product of two complete graphs and all the mutual-visibility problems for the direct product of such graphs as well. We also study all the mutual-visibility problems for the line graphs of complete and complete bipartite graphs. As a consequence of this study, we present several relationships between the mentioned problems and some instances of the classical Tur\'an problem. Moreover, we study the visibility problems for cographs and several non-trivial diameter-two graphs of minimum size.
Comment: 23 pages, 4 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2401.02373
رقم الانضمام: edsarx.2401.02373
قاعدة البيانات: arXiv