New Type of Generalized Closed Sets

Abstract

In this paper, we introduce and study a new type of sets , namely strongly -closed (briefly,- closed) set. This class is strictly between the class of closed sets and the class of gsg- closed sets. It is shown that the class of - open sets forms a topology finer than . Relationships with certain types of closed sets are discussed and basic properties and characterizations are investigated. Further, new characterizations of normal spaces are provided and several preservation theorems of normality are improved.

Key words and phrases: - closed sets, - open sets, normal spaces.