Dice Question Streamline Icon: https://streamlinehq.com

Preservation of strong countable-dimensionality and zero-dimensionality under uniformly continuous surjections Cp(X) -> Cp(Y)

Determine whether, for a uniformly continuous surjection T : Cp(X) -> Cp(Y) with X a compact metrizable strongly countable-dimensional space (respectively, a compact metrizable zero-dimensional space), the space Y is necessarily strongly countable-dimensional (respectively, zero-dimensional).

Information Square Streamline Icon: https://streamlinehq.com

Background

The paper studies uniformly continuous surjections between pointwise-topologized function spaces Cp(X) and Cp(Y) over metrizable spaces. While many invariance results are known for uniform homeomorphisms and linear surjections, substantially less is established for mere uniformly continuous surjections. Prior work showed positive results under stronger hypotheses, such as c-good maps or σ-compactness, but the general case remained unresolved.

Problem 1.2 from [13] asks whether zero-dimensionality and strong countable-dimensionality are preserved under uniformly continuous surjections Cp(X) -> Cp(Y) when X is compact metrizable. The present paper proves preservation under the weaker assumption that T is uniformly continuous and inversely bounded, and for all metrizable (not necessarily compact) X, thereby strengthening previous results but not fully resolving the original question without the inverse boundedness condition.

References

Much less is known about the case when T : Cp(X) -> Cp(Y) is supposed to be only uniformly continuous and surjective. The following open problem has been posed in [13, Question 4.1]. Problem 1.2. Let X be a compact metrizable strongly countable-dimensional [zero-dimensional] space. Suppose that there exists a uniformly continuous sur- jection T : Cp(X) > Cp(Y). Is Y necessarily strongly countable-dimensional [zero-dimensional ?

On uniformly continuous surjections between $C_p$-spaces over metrizable spaces (2408.01870 - Eysen et al., 3 Aug 2024) in Problem 1.2, Introduction (Section 1)