Minimal ideals and cancellation in ßN.
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].
Minimal Models in Homotopy Theory.
Minimal realcompact spaces
Minimal sequential Hausdorff spaces.
Moderation of sigma-finite Borel measures.
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.
Monotone normality and extension of functions
We provide a characterisation of monotone normality with an analogue of the Tietze-Urysohn theorem for monotonically normal spaces as well as answer a question due to San-ou concerning the extension of Urysohn functions in monotonically normal spaces. We also extend a result of van Douwen, giving a characterisation of -spaces in terms of semi-continuous functions, as well as answer another question of San-ou concerning semi-continuous Urysohn functions.
Monotone weak Lindelöfness
The definition of monotone weak Lindelöfness is similar to monotone versions of other covering properties: X is monotonically weakly Lindelöf if there is an operator r that assigns to every open cover U a family of open sets r(U) so that (1) ∪r(U) is dense in X, (2) r(U) refines U, and (3) r(U) refines r(V) whenever U refines V. Some examples and counterexamples of monotonically weakly Lindelöf spaces are given and some basic properties such as the behavior with respect to products and subspaces...
Monotonically normal -separable spaces may not be perfect
A topological space is said to be -separable if has a -closed-discrete dense subset. Recently, G. Gruenhage and D. Lutzer showed that -separable PIGO spaces are perfect and asked if -separable monotonically normal spaces are perfect in general. The main purpose of this article is to provide examples of -separable monotonically normal spaces which are not perfect. Extremely normal -separable spaces are shown to be stratifiable.
More about spaces with a small diagonal
Hušek defines a space X to have a small diagonal if each uncountable subset of X² disjoint from the diagonal has an uncountable subset whose closure is disjoint from the diagonal. Hušek proved that a compact space of weight ω₁ which has a small diagonal will be metrizable, but it remains an open problem to determine if the weight restriction is necessary. It has been shown to be consistent that each compact space with a small diagonal is metrizable; in particular, Juhász and Szentmiklóssy proved...
More on generalized homeomorphisms in topological spaces.
More on rc-Lindelöf sets and almost rc-Lindelöf sets.
More on semi-Urysohn spaces.
More on sg-compact spaces.
More on strongly sequential spaces
Strongly sequential spaces were introduced and studied to solve a problem of Tanaka concerning the product of sequential topologies. In this paper, further properties of strongly sequential spaces are investigated.
More on the product of pseudo radial spaces
It is proved that the product of two pseudo radial compact spaces is pseudo radial provided that one of them is monolithic.
More on tie-points and homeomorphism in ℕ*
A point x is a (bow) tie-point of a space X if X∖x can be partitioned into (relatively) clopen sets each with x in its closure. We denote this as where A, B are the closed sets which have a unique common accumulation point x. Tie-points have appeared in the construction of non-trivial autohomeomorphisms of βℕ = ℕ* (by Veličković and Shelah Steprans) and in the recent study (by Levy and Dow Techanie) of precisely 2-to-1 maps on ℕ*. In these cases the tie-points have been the unique fixed point...
More on -Ohio completeness
We study closed subspaces of -Ohio complete spaces and, for uncountable cardinal, we prove a characterization for them. We then investigate the behaviour of products of -Ohio complete spaces. We prove that, if the cardinal is endowed with either the order or the discrete topology, the space is not -Ohio complete. As a consequence, we show that, if is less than the first weakly inaccessible cardinal, then neither the space , nor the space is -Ohio complete.