On Regularity and Normality via h-Open Sets

We introduce and investigate forms of regularity and normality defined by means of h-open sets. Using the associated topology τ_h = hO(X), we interpret h-regularity as a relative regularity property in which points and closed sets of the original topology are separated by τ_h-open sets, whereas strong h-regularity is precisely the ordinary regularity of (X, τ_h). We establish characterizations of h-regularity, study its preservation under suitable mappings, compare the new notions with their classical counterparts, and examine related separation properties.