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I -Lindelöf spaces.

Al-Zoubi, Khalid, Al-Nashef, Bassam (2004)

International Journal of Mathematics and Mathematical Sciences

In search for Lindelöf C p ’s

Raushan Z. Buzyakova (2004)

Commentationes Mathematicae Universitatis Carolinae

It is shown that if X is a first-countable countably compact subspace of ordinals then C p ( X ) is Lindelöf. This result is used to construct an example of a countably compact space X such that the extent of C p ( X ) is less than the Lindelöf number of C p ( X ) . This example answers negatively Reznichenko’s question whether Baturov’s theorem holds for countably compact spaces.

Initially κ -compact spaces for large κ

Stavros Christodoulou (1999)

Commentationes Mathematicae Universitatis Carolinae

This work presents some cardinal inequalities in which appears the closed pseudo-character, ψ c , of a space. Using one of them — ψ c ( X ) 2 d ( X ) for T 2 spaces — we improve, from T 3 to T 2 spaces, the well-known result that initially κ -compact T 3 spaces are λ -bounded for all cardinals λ such that 2 λ κ . And then, using an idea of A. Dow, we prove that initially κ -compact T 2 spaces are in fact compact for κ = 2 F ( X ) , 2 s ( X ) , 2 t ( X ) , 2 χ ( X ) , 2 ψ c ( X ) or κ = max { τ + , τ < τ } , where τ > t ( p , X ) for all p X .

Inverse sequences with proper bonding maps

Tomás Fernández-Bayort, Antonio Quintero (2010)

Colloquium Mathematicae

Some topological properties of inverse limits of sequences with proper bonding maps are studied. We show that (non-empty) limits of euclidean half-lines are one-ended generalized continua. We also prove the non-existence of a universal object for such limits with respect to closed embeddings. A further result states that limits of end-preserving sequences of euclidean lines are two-ended generalized continua.

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