2025/09/10 by Kąkol, Jerzy, Kurka, Ondřej, Śliwa, Wiesław
#46A03 #54C35 #54G12 #54H05 #FOS: Mathematics #Functional Analysis (math.FA) #General Topology (math.GN)
paper · doi:10.48550/arxiv.2509.08634
For a Tychonoff space X by Cp(X) we denote the space C(X) of continuous real valued functions on X endowed with the pointwise topology. We prove that an infinite compact space X is scattered if and only if every closed infinite-dimensional subspace in Cp(X) contains a copy of c0 (with the pointwise topology) which is complemented in the whole space Cp(X). This provides a Cp-version of the theorem of Lotz, Peck and Porta for Banach spaces C(X) and c0. Applications will be provided. We prove also a Cp-version of Rosenthal's theorem by showing that for an infinite compact X the space Cp(X) contains a closed copy of c0(Γ) (with the pointwise topology) for some uncountable set Γ if and only if X admits an uncountable family of pairwise disjoint open subsets of X. Illustrating examples, additional supplementing Cp-theorems and comments are included.