Abstract
A ring is called a zip ring (Carl Faith coined this term) if every faithful ideal contains a finitely generated faithful ideal. By first proving that a reduced ring is a zip ring if and only if every dense element of the frame of its radical ideals is above a compact dense element, we study algebraic frames with the property stated in the title. We call them zipped. They generalize the coherent frames of radical ideals of zip rings, but (unlike coherent frames) they need not be compact. The class of zipped algebraic frames is closed under finite products, but not under infinite products. If the coproduct of two algebraic frames is zipped, then each cofactor is zipped. If the ring is not necessarily reduced, then its frame of radical ideals is zipped precisely when the ring satisfies what in the literature is called the weak zip property. For a Tychonoff space X, we show that C(X) is a zip ring if and only if X is a finite discrete space.
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Acknowledgements
We are most grateful to the referee for comments and suggestions that have improved the first version of this paper. The first-named author acknowledges funding from the National Research Foundation of South Africa under Grant 129256.
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Presented by W. Wm. McGovern.
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Dube, T., Blose, S. Algebraic frames in which dense elements are above dense compact elements. Algebra Univers. 84, 3 (2023). https://doi.org/10.1007/s00012-022-00799-w
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DOI: https://doi.org/10.1007/s00012-022-00799-w