scholarly journals nIαg-Compact spaces and nIαg-Lindelof spaces in nano ideal topological spaces

2020 ◽  
Author(s):  
M. Parimala ◽  
D. Arivuoli ◽  
R. Perumal ◽  
S. Krithika
Keyword(s):  
Topological Spaces ◽  
Compact Spaces

On the Dimension Modulo Classes of Topological Spaces and Free Topological Groups

2003 ◽  
Vol 10 (2) ◽  
pp. 209-222
Author(s):  
I. Bakhia
Keyword(s):  
Wide Class ◽  
Sufficient Conditions ◽  
Topological Spaces ◽  
Topological Groups ◽  
Compact Spaces ◽  
Topological Semigroups

Abstract Functions of dimension modulo a (rather wide) class of spaces are considered and the conditions are found, under which the dimension of the product of spaces modulo these classes is equal to zero. Based on these results, the sufficient conditions are established, under which spaces of free topological semigroups (in the sense of Marxen) and spaces of free topological groups (in the sense of Markov and Graev) are zero-dimensional modulo classes of compact spaces.

scholarly journals A note on fragmentable topological spaces

1994 ◽  
Vol 49 (1) ◽  
pp. 91-100
Author(s):  
Toshihiro Nagamizu
Keyword(s):  
Topological Spaces ◽  
Compact Spaces

We extend the results of N.K. Ribarska and A.V. Arhangel'skiĭ to the class of strongly countably complete spaces. And we show another characterisation of Eberlein and Radon-Nikodým compact spaces.

scholarly journals Some classes of E-Compactness

1972 ◽  
Vol 13 (4) ◽  
pp. 492-500 ◽  
Author(s):  
Robert L. Blefko
Keyword(s):  
Closed Subset ◽  
Unit Interval ◽  
Related Question ◽  
Topological Spaces ◽  
Completely Regular ◽  
Compact Spaces

Mrowka and Engleking [1] have recently introduced a notion more general than that of compactness. Perhaps the most convenient direction at departure is the following: for spaces X and E, X is said to be E-compact if X is topologically embeddable as a closed subset of a product Em for some cardinal m, in which case we write X ⊂cl Em. More generally, X is said to be E-completely regular if X is topologically embeddable in a product Em for some m. For example, if we take E to be the unit interval I, we obtain the class of compact spaces and completely regular spaces, respectively, as is well-known. The question then arises, of course, given a space E, what spaces are compact with respect to it? A related question, to which we address ourselves in this note, is the following. Denote by K[E] all those topological spaces which are E-compact. Then we ask: are there very many distinct E-compact classes? It will develop that there are indeed quite a large number of such classes.

A note on λ-compact spaces

2013 ◽  
Vol 63 (6) ◽  
Author(s):  
O. Karamzadeh ◽  
M. Namdari ◽  
M. Siavoshi
Keyword(s):  
Topological Space ◽  
Topological Spaces ◽  
Hausdorff Spaces ◽  
Compact Spaces

AbstractWe extend the well-known and important fact that “a topological space X is compact if and only if every ideal in C(X) is fixed”, to more general topological spaces. Some interesting consequences are also observed. In particular, the maximality of compact Hausdorff spaces with respect to the property of compactness is generalized and the topological spaces with this generalized property are characterized.

scholarly journals Soft Simply Compact Spaces

2020 ◽  
pp. 108-113
Author(s):  
S. Noori ◽  
Y. Y. Yousif
Keyword(s):  
Topological Spaces ◽  
Compact Spaces ◽  
Open Set ◽  
Separation Axioms

The aim of this research is to use the class of soft simply open set to define new types of separation axioms in soft topological spaces. We also introduce and study the concept of soft simply compactness.

scholarly journals $\mu$-compactness with respect to a hereditary class

2015 ◽  
Vol 34 (2) ◽  
pp. 231-236 ◽  
Author(s):  
C. Carpintero ◽  
E. Rosas ◽  
Margot Salas-Brown ◽  
J. Sanabria
Keyword(s):  
Topological Spaces ◽  
Compact Spaces ◽  
Hereditary Class

We define and study the notion of compactness in generalized topological spaces with respect to a hereditary class: $\mu\mathcal{H}$-compact spaces.

Pointwise Compact Spaces

1973 ◽  
Vol 16 (4) ◽  
pp. 545-549 ◽  
Author(s):  
Pedro Morales
Keyword(s):  
Topological Spaces ◽  
Locally Compact ◽  
Separation Axiom ◽  
Compact Spaces

In 1962, J. M. G. Fell [5] indicated the important role played by certain topological spaces which, though locally compact in a specialized sense, do not, in general, satisfy even the weakest separation axiom. He called them "locally compact". These were called "punktal kompakt" by Flachsmeyer [6] and to avoid confusion, we shall call them pointwise compact spaces.

Essentials of General Topology

2021 ◽  
pp. 191-244
Author(s):  
Adel N. Boules
Keyword(s):  
Topological Spaces ◽  
Hausdorff Spaces ◽  
Locally Compact ◽  
Compact Spaces ◽  
Section 8 ◽  
Finite Products ◽  
The One ◽  
One Point Compactification ◽  
Locally Compact Spaces ◽  
Metrization Theorem

The first eight sections of this chapter constitute its core and are generally parallel to the leading sections of chapter 4. Most of the sections are brief and emphasize the nonmetric aspects of topology. Among the topics treated are normality, regularity, and second countability. The proof of Tychonoff’s theorem for finite products appears in section 8. The section on locally compact spaces is the transition between the core of the chapter and the more advanced sections on metrization, compactification, and the product of infinitely many spaces. The highlights include the one-point compactification, the Urysohn metrization theorem, and Tychonoff’s theorem. Little subsequent material is based on the last three sections. At various points in the book, it is explained how results stated for the metric case can be extended to topological spaces, especially locally compact Hausdorff spaces. Some such results are developed in the exercises.

Countably Compact Spaces and Martin's Axiom

1978 ◽  
Vol 30 (02) ◽  
pp. 243-249 ◽  
Author(s):  
William Weiss
Keyword(s):  
Set Theory ◽  
Normal Space ◽  
Topological Spaces ◽  
Compact Spaces ◽  
Countably Compact Space ◽  
Countably Compact ◽  
Countably Compact Spaces ◽  
Perfectly Normal Space ◽  
The Relationship ◽  
Perfectly Normal

The relationship between compact and countably compact topological spaces has been studied by many topologists. In particular an important question is: “What conditions will make a countably compact space compact?” Conditions which are “covering axioms” have been extensively studied. The best results of this type appear in [19]. We wish to examine countably compact spaces which are separable or perfectly normal. Recall that a space is perfect if and only if every closed subset is a Gδ, and that a space is perfectly normal if and only if it is both perfect and normal. We show that the following statement follows from MA +┐ CH and thus is consistent with the usual axioms of set theory: Every countably compact perfectly normal space is compact. This result is Theorem 3 and can be understood without reading much of what goes before.

scholarly journals Weakly m-compact via a hereditary class

2021 ◽  
Vol 39 (3) ◽  
pp. 123-135
Author(s):  
Abdo Qahis ◽  
Heyam Hussain AlJarrah ◽  
Takashi Noiri
Keyword(s):  
Topological Spaces ◽  
Compact Spaces ◽  
Hereditary Class ◽  
Compact Subsets

The aim of this paper is to introduce and study some types of m-compactness with respect to a hereditary class called weakly mH-compact spaces and weakly mH-compact subsets. We will provide several characterizations of weakly mH-compact spaces and investigate their relationships with some other classes of generalized topological spaces.

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