English

A number of properties enjoyed by two specially constructed topologies on $C(X)$

General Topology 2026-01-29 v2

Abstract

If II is an ideal in the ring C(X)C(X) of all real valued continuous functions defined over a Tychonoff space XX, then XX is called II-pseudocompactpseudocompact if the set XZ[I]X\setminus \bigcap Z[I] is a bounded subset of XX. Corresponding to II, the mIm^I-topology and uIu^I-topology on C(X)C(X), generalizing the well-known mm-topology and uu-topology in C(X)C(X) respectively are already there in the literature. It is proved amongst others that the mIm^I-topology is first countable if and only if the uIu^I-topology= mIm^I-topology on C(X)C(X) if and only if XX is II-pseudocompactpseudocompact. A special case of this result on choosing I=C(X)I=C(X) reads: the uu-topology and mm-topology on C(X)C(X) coincide if and only if XX is pseudocompact. It is established that the mIm^I-topology on C(X)C(X) is second countable if and only if it is 0\aleph_0-boundedbounded if and only if XX is compact, metrizable and I=C(X)I=C(X). Furthermore it is realized that the mIm^I topology on C(X)C(X) is hemicompact if and only if it is σ\sigma-compact if and only if this topology is HH-boundedbounded if and only if XX is finite and I=C(X)I=C(X).

Keywords

Cite

@article{arxiv.2508.14651,
  title  = {A number of properties enjoyed by two specially constructed topologies on $C(X)$},
  author = {Soumajit Dey and Sudip Kumar Acharyya and Dhananjoy Mandal},
  journal= {arXiv preprint arXiv:2508.14651},
  year   = {2026}
}