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arXiv · 2501.18574

Inductive methods for counting number fields

Brandon Alberts·Robert J. Lemke Oliver·Jiuya Wang·Melanie Matchett Wood
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Abstract

We give a new method for counting extensions of a number field asymptotically by discriminant, which we employ to prove many new cases of Malle's Conjecture and counterexamples to Malle's Conjecture. We consider families of extensions whose Galois closure is a fixed permutation group $G$. Our method relies on having asymptotic counts for $T$-extensions for some normal subgroup $T$ of $G$, uniform bounds for the number of such $T$-extensions, and possibly weak bounds on the asymptotic number of $G/T$-extensions. However, we do not require that most $T$-extensions of a $G/T$-extension are $G$-extensions. Our new results use $T$ either abelian or $S_3^m$, though our framework is general.

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Brandon Alberts, Robert J. Lemke Oliver, Jiuya Wang, Melanie Matchett Wood. 2025-01-30. Inductive methods for counting number fields. https://arxiv.org/abs/2501.18574

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