2021/05/18 by Klavžar, Sandi, Kuziak, Dorota, Peterin, Iztok +1
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.2105.08391
Let G be a graph. The Steiner distance of W⊆ V(G) is the minimum size of a connected subgraph of G containing W. Such a subgraph is necessarily a tree called a Steiner W-tree. The set A⊆ V(G) is a k-Steiner general position set if V(TB)∩ A = B holds for every set B⊆ A of cardinality k, and for every Steiner B-tree TB. The k-Steiner general position number \rm sgpk(G) of G is the cardinality of a largest k-Steiner general position set in G. Steiner cliques are introduced and used to bound \rm sgpk(G) from below. The k-Steiner general position number is determined for trees, cycles and joins of graphs. Lower bounds are presented for split graphs, infinite grids and lexicographic products. The lower bound for the latter products leads to an exact formula for the general position number of an arbitrary lexicographic product.