In 1993, Henn, Lannes and Schwartz established a very strong relation between the Steenrod algebra and the category F.p/ of functors from the category E of finite dimensional Fp –vector spaces to the category E of all Fp –vector spaces, where Fp is the prime field with p elements [5]. To be more precise, they study the category U of unstable modules over the Steenrod algebra localized away from...

In this paper, we define topological hyperrings and study their basic concepts which supported by illustrative examples. We show some differences between topological rings and topological hyperrings. Also, by the fundamental relation $\Gamma^{*}$, we indicate the role of complete parts (saturated subsets) and complete hyperrings in topological hyperrings and specially we show that if every (clo...

In recent years, models of spatial relations have attracted much attention from GIS community, especially topological relations. In this paper, some basic topologic models for spatial entities in both vector and raster spaces are discussed. To make the concepts more formalized, some new concepts from a new branch of mathematics -pansystems -are adopted. In doing so, the basic concepts of pansys...

In this paper we study topological lower bounds on the number of zeros of closed 1-forms without Morse type assumptions. We prove that one may always find a representing closed 1-form having at most one zero. We introduce and study a generalization cat(X, ξ) of the notion of Lusternik Schnirelman category, depending on a topological space X and a 1-dimensional real cohomology class ξ ∈ H1(X;R)....

In this paper we study topological lower bounds on the number of zeros of closed 1-forms without Morse type assumptions. We prove that one may always find a representing closed 1-form having at most one zero. We introduce and study a generalization cat(X, ξ) of the notion of Lusternik Schnirelman category, depending on a topological space X and a 1-dimensional real cohomology class ξ ∈ H1(X;R)....

In this paper we introduce the notion of an F-metric, as a function valued distance mapping, on a set X and we investigate the theory of F-metric spaces. We show that every metric space may be viewed as an F-metric space and every F-metric space (X, δ) can be regarded as a topological space (X, τδ). In addition, we prove that the category of the so-called extended Fmetric spaces properly contai...