L’espace des fonctions localement sur un espace compactologique
Locally connected images of ordered compacta
Locally constant functions
Let X be a compact Hausdorff space and M a metric space. is the set of f ∈ C(X,M) such that there is a dense set of points x ∈ X with f constant on some neighborhood of x. We describe some general classes of X for which is all of C(X,M). These include βℕ, any nowhere separable LOTS, and any X such that forcing with the open subsets of X does not add reals. In the case where M is a Banach space, we discuss the properties of as a normed linear space. We also build three first countable Eberlein...
Locally nice spaces under Martin's axiom
Locally well-behaved paracompacta in shape theory
Maximal nowhere dense -sets in basically disconnected spaces and -spaces
In [5] the following question was put: are there any maximal n.d. sets in ? Already in [9] the negative answer (under MA) to this question was obtained. Moreover, in [9] it was shown that no -set can be maximal n.d. In the present paper the notion of a maximal n.d. -set is introduced and it is proved that under CH there is no such a set in . The main results are Theorem 1.10 and especially Theorem 2.7(ii) (with Example in Section 3) in which the problem of the existence of maximal n.d. -sets...
Means on scattered compacta
We prove that a separable Hausdor_ topological space X containing a cocountable subset homeomorphic to [0, ω1] admits no separately continuous mean operation and no diagonally continuous n-mean for n ≥ 2.
Measures of Lindelöf and separability in approach spaces.
Measures on Corson compact spaces
We prove that the statement: "there is a Corson compact space with a non-separable Radon measure" is equivalent to a number of natural statements in set theory.
Metrization criteria for compact groups in terms of their dense subgroups
According to Comfort, Raczkowski and Trigos-Arrieta, a dense subgroup D of a compact abelian group G determines G if the restriction homomorphism Ĝ → D̂ of the dual groups is a topological isomorphism. We introduce four conditions on D that are necessary for it to determine G and we resolve the following question: If one of these conditions holds for every dense (or -dense) subgroup D of G, must G be metrizable? In particular, we prove (in ZFC) that a compact abelian group determined by all its...
Minimal -spaces are countably compact
In this paper we show that a minimal space in which compact subsets are closed is countably compact. This answers a question posed in [1].
Monomorphisms in spaces with Lindelöf filters
is the category of spaces with filters: an object is a pair , a compact Hausdorff space and a filter of dense open subsets of . A morphism is a continuous function for which whenever . This category arises naturally from considerations in ordered algebra, e.g., Boolean algebra, lattice-ordered groups and rings, and from considerations in general topology, e.g., the theory of the absolute and other covers, locales, and frames, though we shall specifically address only one of these...
Monotone meta-Lindelöf spaces
In this paper, we study the monotone meta-Lindelöf property. Relationships between monotone meta-Lindelöf spaces and other spaces are investigated. Behaviors of monotone meta-Lindelöf -spaces in their linearly ordered extensions are revealed.
More on sg-compact spaces.
More reflections on compactness
We consider the question of when , where is the elementary submodel topology on X ∩ M, especially in the case when is compact.
Mutually compactificable topological spaces.
Nets and compactness
Non-accessible points in extremally disconnected compact spaces I
Noncommutative Valdivia compacta
We prove some generalizations of results concerning Valdivia compact spaces (equivalently spaces with a commutative retractional skeleton) to the spaces with a retractional skeleton (not necessarily commutative). Namely, we show that the dual unit ball of a Banach space is Corson provided the dual unit ball of every equivalent norm has a retractional skeleton. Another result to be mentioned is the following. Having a compact space , we show that is Corson if and only if every continuous image...