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Krzysztof Zakrzewski

Publications and source records attributed to Krzysztof Zakrzewski.

2 recordsLinked to original sources

Function spaces on Corson-like compacta

For an index set $Γ$ and a cardinal number $κ$ the $Σ_κ$-product of real lines $Σ_κ(\mathbb{R}^Γ)$ consist of all elements of $\mathbb{R}^Γ$ with $<κ$ nonzero coordinates. A compact space is $κ$-Corson if it can be embedded into $Σ_κ(\mathbb{R}^Γ)$ for some $Γ$. We also consider a class of compact spaces wider than the class of $ω$-Corson compact spaces, investigated by Nakhmanson and Yakovlev as well as Marciszewski, Plebanek and Zakrzewski called $NY$ compact spaces. For a Tychonoff space $X$, let $C_{p}(X)$ be the space of real continuous functions on the space $X$, endowed with the pointwise convergence topology. We present here a characterisation of $κ$-Corson compact spaces $K$ for regular, uncountable cardinal numbers $κ$ in terms of function spaces $C_{p}(K)$, extending a theorem of Bell and Marciszewski and a theorem of Pol. We also prove that classes of $NY$ compact spaces and $ω$-Corson compact spaces $K$ are preserved by linear homeomorphisms of function spaces $C_{p}(K)$.

math.GN↗

Digging into the classes of $κ$-Corson compact spaces

For any cardinal number $κ$ and an index set $Γ$, $Σ_κ$-product of real lines consists of elements of ${\mathbb R}^Γ$ having $<κ$ nonzero coordinates. A compact space $K$ is $κ$-Corson compact if it can be embedded into such a space for some $Γ$. The class of ($ω_1$-)Corson compact spaces has been intensively studied over last decades. We discuss properties of $κ$-Corson compacta for various cardinal numbers $κ$ as well as properties of related Boolean algebras and spaces of continuous functions. We present here a detailed discussion of the class of $ω$-Corson compacta extending the results of Nakhmanson and Yakovlev. For $κ>ω$, our results on $κ$-Corson compact spaces are related to the line of research originated by Kalenda and Bell and Marciszewski, and continued by Bonnet, Kubis and Todorcevic in their recent paper.

math.GN↗