On divisor topology of modules over domains

OpenAlex · İngilizce

Let M be a module over a domain R and M#={0≠m∈M:Rm≠M} be the set of all nonzero nongenerators of M. Consider the following equivalence relation ∼ on M# given by m∼n if and only if Rm=Rn for every m,n∈M#. Let EC(M#) be the set of all equivalence classes of M# with respect to ∼. In this paper, we construct a topology on EC(M#) which is called the divisor topology of M and is denoted by D(M). Actually, D(M) is an extension of the divisor topology D(R) over domains to modules in the sense of Yiğit and Koç. We investigate separation axioms Ti for every 0≤i≤5, first and second countability, connectivity, compactness, nested property, and Noetherian property on D(M). Also, we characterize some important classes of modules such as uniserial modules, simple modules, vector spaces, and finitely cogenerated modules in terms of D(M). Furthermore, we prove that D(M) is a Baire space for factorial modules. Finally, we introduce and study pseudo simple modules which is a new generalization of simple modules, and use them to determine when D(M) is a discrete space.