The total graph of unfaithful submodules of a module over reversible rings

Abstract

Let [Formula: see text] be an associative ring with identity. A ring [Formula: see text] is called reversible if [Formula: see text], then [Formula: see text] for [Formula: see text]. The total graph of unfaithful submodules of a module [Formula: see text] over a reversible ring [Formula: see text], denoted by [Formula: see text], is a graph whose vertices are all nonzero unfaithful submodules of [Formula: see text] and two distinct vertices [Formula: see text] and [Formula: see text] are adjacent if [Formula: see text] is unfaithful. In this paper, we determine the diameter and girth of [Formula: see text]. Also, we study some combinatorial properties of [Formula: see text] such as independence number and clique number. Moreover, we study the case that the degree of a vertex of [Formula: see text] is finite.