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arXiv · 2610.38457

Class groups of polynomial Krull domains

Djamila Ait Elhadi·Giulio Peruginelli
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Abstract

A polynomial Krull domain is a Krull domain contained between $\mathbb Z[X]$ and $\mathbb Q[X]$. The domains of this class are precisely the Noetherian integrally closed domains between these polynomial rings by a result of Heinzer, and they have been recently classified by Chang and the second author of this paper as rings of polynomials which are integer-valued over a finite set of ultrametric balls in $\mathbb C_p$, as $p$ ranges through the set of primes in $\mathbb Z$. We show here that every ideal class of a polynomial Krull domain contains a prime ideal. Furthermore, given such a Krull domain $R$, we prove that there exists a polynomial Krull domain $R'$ that is Dedekind, contains $R$ and has the same class group as $R$.

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Djamila Ait Elhadi, Giulio Peruginelli. 2026-10-28. Class groups of polynomial Krull domains. https://arxiv.org/abs/2610.38457

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