On spaces whose product with every Lindelöf space is Lindelöf
Displaying 581 – 600 of 1013
On spaces with the property of weak approximation by points
Angelo Bella (1994)
Commentationes Mathematicae Universitatis Carolinae
A sufficient condition that the product of two compact spaces has the property of weak approximation by points (briefly WAP) is given. It follows that the product of the unit interval with a compact WAP space is also a WAP space.
On -starcompact spaces.
Song, Yan-Kui (2007)
Bulletin of the Malaysian Mathematical Sciences Society. Second Series
On -starcompact spaces
Yan-Kui Song (2006)
Czechoslovak Mathematical Journal
A space is -starcompact if for every open cover of there exists a Lindelöf subset of such that We clarify the relations between -starcompact spaces and other related spaces and investigate topological properties of -starcompact spaces. A question of Hiremath is answered.
On subsets of Alexandroff duplicates
Takemi Mizokami (2005)
Commentationes Mathematicae Universitatis Carolinae
We characterize the subsets of the Alexandroff duplicate which have a G-diagonal and the subsets which are M-spaces in the sense of Morita.
On subspaces of pseudo-radial spaces
Jin Yuan Zhou (1993)
Commentationes Mathematicae Universitatis Carolinae
It is proved that, under the Martin’s Axiom, every -space with countable tightness is a subspace of some pseudo-radial space. We also give several characterizations of subspaces of pseudo-radial spaces and conclude that being a subspace of a pseudo-radial space is a local property.
On subspaces of the Pixley-Roy example
Szymon Plewik (1981)
Colloquium Mathematicae
On supercomplete uniform spaces IV: Countable products
Aarno Hohti, Jan Pelant (1990)
Fundamenta Mathematicae
On supercomplete uniform spaces V: Tamano's product problem
Aarno Hohti (1990)
Fundamenta Mathematicae
On symmetric products
Juliusz Olędzki (1988)
Fundamenta Mathematicae
On Telgársky's question concerning β-favorability of the strong Choquet game
László Zsilinszky (2013)
Colloquium Mathematicae
Answering a question of Telgársky in the negative, it is shown that there is a space which is β-favorable in the strong Choquet game, but all of its nonempty -subspaces are of the second category in themselves.
On the 2-homogeneity of Cartesian products
Krystyna Kuperberg, W. Kuperberg, W. Transue (1980)
Fundamenta Mathematicae
On the cardinality of power homogeneous Hausdorff spaces
G. J. Ridderbos (2006)
Fundamenta Mathematicae
We prove that the cardinality of power homogeneous Hausdorff spaces X is bounded by . This inequality improves many known results and it also solves a question by J. van Mill. We further introduce Δ-power homogeneity, which leads to a new proof of van Douwen’s theorem.
On the category of topological topologies
Maria Cristina Pedicchio (1984)
Cahiers de Topologie et Géométrie Différentielle Catégoriques
On the class of all spaces of weight not greater than ω_1 whose Cartesian product with every Lindelöf space is Lindelöf
K. Alster (1988)
Fundamenta Mathematicae
On the co-completeness of the category of Hausdorff uniform spaces.
Bautista, Serafín, Varela, Januario (1997)
Revista Colombiana de Matemáticas
On the Compactness and Countable Compactness of in ZF
Kyriakos Keremedis, Evangelos Felouzis, Eleftherios Tachtsis (2007)
Bulletin of the Polish Academy of Sciences. Mathematics
In the framework of ZF (Zermelo-Fraenkel set theory without the Axiom of Choice) we provide topological and Boolean-algebraic characterizations of the statements " is countably compact" and " is compact"
On the construction of the extensional topological hull
I. W. Alderton, F. Schwartz, S. Weck-Schwarz (1994)
Cahiers de Topologie et Géométrie Différentielle Catégoriques
On the deficiency of product spaces
Calvin F. K. Jung (1973)
Colloquium Mathematicae
On the density of the hyperspace of a metric space
Alberto Barbati, Camillo Costantini (1997)
Commentationes Mathematicae Universitatis Carolinae
We calculate the density of the hyperspace of a metric space, endowed with the Hausdorff or the locally finite topology. To this end, we introduce suitable generalizations of the notions of totally bounded and compact metric space.