in this paper a particular case of z-ideals, called strongly z-ideal, is defined by introducing zero sets in pointfree topology. we study strongly z-ideals, their relation with z-ideals and the role of spatiality in this relation. for strongly z-ideals, we analyze prime ideals using the concept of zero sets. moreover, it is proven that the intersection of all zero sets of a prime ideal of c(l),...

Context. IRAS observations show the existence of a correlation between the infrared luminosity L IR and dust temperature T d in star-forming galaxies, in which larger L IR leads to higher dust temperature. The L IR –T d relation is commonly seen as reflecting the increase in dust temperature in galaxies with higher star formation rate (SFR). Even though the correlation shows a significant amoun...

In this paper a particular case of z-ideals, called strongly z-ideal, is defined by introducing zero sets in pointfree topology. We study strongly z-ideals, their relation with z-ideals and the role of spatiality in this relation. For strongly z-ideals, we analyze prime ideals using the concept of zero sets. Moreover, it is proven that the intersection of all zero sets of a prime ideal of C(L),...

Let $L$ be an integral and commutative quantale. In this paper, by fuzzifying the notion of generalized neighborhood systems, the notion of $L$-fuzzy generalized neighborhoodsystem is introduced and then a pair of lower and upperapproximation operators based on it are defined and discussed. It is proved that these approximation operators include generalized neighborhood system...

There is a canonical way to associate two simplicial complexes K, L to any relation R ⊂ X×Y . Moreover, the geometric realizations of K and L are homotopy equivalent. This was studied in the fifties by C.H. Dowker [8]. In this article we prove a Galois-type correspondence for relations R ⊂ X × Y when X is fixed and use these constructions to investigate finite posets (or equivalently, finite T0...

Aims. In this paper we re-visit the observational relation between X–ray luminosity and temperature for high-z galaxy clusters and compare it with the local L X –T and with theoretical models. Methods. To these ends we use a sample of 17 clusters extracted from the Chandra archive supplemented with additional clusters from the literature, either observed by Chandra or XMM–Newton, to form a fina...