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Do rings with ideal covering number p+1 always have a factor ring isomorphic to one of the constructed families?

Ascertain whether every ring R for which an ideal covering number equals p+1 (for some prime p) necessarily has a factor ring isomorphic to one of the explicit example families R1, R2, R3, or R4 constructed in this work.

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Background

Theorem 1.1 constructs four infinite families of rings (R1–R4) that achieve the sharp lower bound p+1 in various combinations of left, right, and two-sided ideal coverings. Corollary 1.2 fully characterizes the case of ideal covering number 3 via specific factor rings in small matrix rings over Z_2 and Z_4.

This suggests a potential structural principle: perhaps any ring attaining the minimal value p+1 must admit a factor ring isomorphic to one of these canonical examples. The paper leaves open whether such a reduction via factor rings always exists.

References

We conclude with a few natural open questions. Does every ring with ideal covering number $p+1$ necessarily have a factor ring isomorphic to one of the examples constructed in Theorem \ref{main}?

Rings as unions of proper ideals (2508.05455 - Chen, 7 Aug 2025) in Section 3 (Concluding Remarks), final list of open questions, item 4