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Ideals of functions with compact support in the integer-valued case

  • Themba Dube EMAIL logo , Oghenetega Ighedo und Batsile Tlharesakgosi
Veröffentlicht/Copyright: 4. Dezember 2022
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Abstract

For a zero-dimensional Hausdorff space X, denote, as usual, by C(X, ℤ) the ring of continuous integer-valued functions on X. If fC(X, ℤ), denote by Z(f) the set of all points of X that are mapped to 0 by f. The set

CK(X,Z)={fC(X,Z)clX(XZ(f)) is compact}

is the integer-valued analogue of the ideal of functions with compact support in C(X). By first working in the category of locales and then interpreting the results in spaces, we characterize this ideal in several ways. Writing ζ X for the Banaschewski compactification of X, we also explore some properties of ideals of C(X, ℤ) associated with subspaces of ζ X analogously to how one associates, for any Tychonoff space Y, subsets of β Y with ideals of C(Y).

MSC 2010: 06D22; 13A15; 54C30; 54G05
  1. (Communicated by L’ubica Holá)

Acknowledgement

Thanks are due to the referee for helpful comments that culminated in an improved paper.

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Received: 2021-07-04
Accepted: 2021-09-08
Published Online: 2022-12-04
Published in Print: 2022-12-16

© 2022 Mathematical Institute Slovak Academy of Sciences

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