The large sum graph related to comultiplication modules
  Let R be a commutative ring and M be an R-module. We define the large sum graph, denoted by \acute{G}(M), as a graph with the vertex set of non-large submodules of M and two distinct vertices are adjacent if and only if N + K is a non-large submodule of M. In this article, we investigate the connection between the graph-theoretic properties of \acute{G}(M) and some algebraic properties of M when M is a comultiplication R-module. 
H. Ansari-Toroghy and F. Mahboobi-Abkenar
math.AC