Local (Outer) Multiset Dimensions of Graphs

Abstract: Let $G$ be a finite, connected, undirected, and simple graph and $W$ be a set of vertices in $G$. A representation multiset of a vertex $u$ in $V(G)$ with respect to $W$ is defined as the multiset of distances between $u$ and the vertices in $W$. If every two adjacent vertices in $V(G)$ have a distinct multiset representation, the set $W$ is called a local multiset resolving set of $G$. If $G$ has a local multiset resolving set, then this set with the smallest cardinality is called the local multiset basis, and its cardinality is the local multiset dimension of $G$. Otherwise, $G$ is said to have an infinite local multiset dimension. On the other hand, if every two adjacent vertices in $V(G) \backslash W$ have a distinct representation multiset, the set $W$ is called a local outer multiset resolving set of $G$. Such a set with the smallest cardinality is called the local outer multiset basis, and its cardinality is the local outer multiset dimension of $G$. Unlike the local multiset dimension, every graph has a finite local outer multiset dimension. This paper presents some basic properties of local (outer) multiset dimensions, including lower bounds for the dimensions and a necessary condition for a finite local multiset dimension. We also determine local (outer) multiset dimensions for some graphs of small diameter.