Displaying 121 – 140 of 212

Showing per page

On ω -resolvable and almost- ω -resolvable spaces

J. Angoa, M. Ibarra, Angel Tamariz-Mascarúa (2008)

Commentationes Mathematicae Universitatis Carolinae

We continue the study of almost- ω -resolvable spaces beginning in A. Tamariz-Mascar’ua, H. Villegas-Rodr’ıguez, Spaces of continuous functions, box products and almost- ω -resoluble spaces, Comment. Math. Univ. Carolin. 43 (2002), no. 4, 687–705. We prove in ZFC: (1) every crowded T 0 space with countable tightness and every T 1 space with π -weight 1 is hereditarily almost- ω -resolvable, (2) every crowded paracompact T 2 space which is the closed preimage of a crowded Fréchet T 2 space in such a way that the...

Pairwise weakly Hausdorff spaces

M. E. El-Shafei (2005)

Archivum Mathematicum

In this paper, we introduce and investigate the notion of weakly Hausdorffness in bitopological spaces by using the convergent of nets. Several characterizations of this notion are given. Some relationships between these spaces and other spaces satisfying some separation axioms are studied.

Partial discretization of topologies

M. Bonanzinga, F. Cammaroto, M. V. Matveev (2000)

Bollettino dell'Unione Matematica Italiana

In questo lavoro daremo una construzione che aumenta il numero di sottospazi chiusi e discreti dello spazio e daremo alcune applicazioni di tale construzione.

Quasicontinuous spaces

Jing Lu, Bin Zhao, Kaiyun Wang, Dong Sheng Zhao (2022)

Commentationes Mathematicae Universitatis Carolinae

We lift the notion of quasicontinuous posets to the topology context, called quasicontinuous spaces, and further study such spaces. The main results are: (1) A T 0 space ( X , τ ) is a quasicontinuous space if and only if S I ( X ) is locally hypercompact if and only if ( τ S I , ) is a hypercontinuous lattice; (2) a T 0 space X is an S I -continuous space if and only if X is a meet continuous and quasicontinuous space; (3) if a C -space X is a well-filtered poset under its specialization order, then X is a quasicontinuous space...

Quasi-orbit spaces associated to T₀-spaces

C. Bonatti, H. Hattab, E. Salhi (2011)

Fundamenta Mathematicae

Let G ⊂ Homeo(E) be a group of homeomorphisms of a topological space E. The class of an orbit O of G is the union of all orbits having the same closure as O. Let E/G̃ be the space of classes of orbits, called the quasi-orbit space. We show that every second countable T₀-space Y is a quasi-orbit space E/G̃, where E is a second countable metric space. The regular part X₀ of a T₀-space X is the union of open subsets homeomorphic to ℝ or to 𝕊¹. We give a characterization of the spaces X with finite...

R -continuous functions.

Konstadilaki-Savvopoulou, Ch., Janković, D. (1992)

International Journal of Mathematics and Mathematical Sciences

Currently displaying 121 – 140 of 212