English
Related papers

Related papers: Cohen-Lenstra Moments for Some Nonabelian Groups

200 papers

Cohen and Lenstra have given a heuristic which, for a fixed odd prime $p$, leads to many interesting predictions about the distribution of $p$-class groups of imaginary quadratic fields. We extend the Cohen-Lenstra heuristic to a…

Number Theory · Mathematics 2014-12-11 Nigel Boston , Michael R. Bush , Farshid Hajir

In this paper we give a conjecture for the average number of unramified $G$-extensions of a quadratic field for any finite group $G$. The Cohen-Lenstra heuristics are the specialization of our conjecture to the case that $G$ is abelian of…

Number Theory · Mathematics 2019-03-20 Melanie Matchett Wood , Philip Matchett Wood

Boston, Bush, and Hajir have developed heuristics, extending the Cohen-Lenstra heuristics, that conjecture the distribution of the Galois groups of the maximal unramified pro-p extensions of imaginary quadratic number fields for p an odd…

Number Theory · Mathematics 2019-02-20 Nigel Boston , Melanie Matchett Wood

For a finite group $\Gamma$, we study the distribution of the Galois group $G_{\emptyset}^{\#}(K)$ of the maximal unramified extension of $K$ that is split completely at $\infty$ and has degree prime to $|\Gamma|$ and $\textit{Char}(K)$, as…

Number Theory · Mathematics 2025-07-30 Yuan Liu , Ken Willyard

We consider the Galois group $G_2(K)$ of the maximal unramified $2$-extension of $K$ where $K/\mathbb{Q}$ is cyclic of degree $3$. We also consider the group $G^+_2(K)$ where ramification is allowed at infinity. In the spirit of the…

Number Theory · Mathematics 2021-01-01 Nigel Boston , Michael R. Bush

Let $p$ be an odd prime. For a number field $K$, we let $K_\infty$ be the maximal unramified pro-$p$ extension of $K$; we call the group $\mathrm{Gal}(K_\infty/K)$ the $p$-class tower group of $K$. In a previous work, as a non-abelian…

Number Theory · Mathematics 2018-03-13 Nigel Boston , Michael R. Bush , Farshid Hajir

For a Galois extension $K/\mathbb{F}_q(t)$ of Galois group $\Gamma$ with $\gcd(q,|\Gamma|)=1$, we define an invariant $\omega_K$, and show that it determines the Weil pairing of the curve corresponding to $K$ and it descends to the…

Number Theory · Mathematics 2022-12-21 Yuan Liu

The main purpose of the paper is to formulate a probabilistic model for Arakelov class groups in families of number fields, offering a correction to the Cohen--Lenstra--Martinet heuristic on ideal class groups. To that end, we show that…

Number Theory · Mathematics 2024-03-28 Alex Bartel , Henri Johnston , Hendrik W. Lenstra

We study the asymptotics conjecture of Malle for dihedral groups $D_\ell$ of order $2\ell$, where $\ell$ is an odd prime. We prove the expected lower bound for those groups. For the upper bounds we show that there is a connection to class…

Number Theory · Mathematics 2007-05-23 Jürgen Klüners

We compute all the moments of a normalization of the function which counts unramified $H_{8}$-extensions of quadratic fields, where $H_{8}$ is the quaternion group of order 8, and show that the values of this function determine a constant…

Number Theory · Mathematics 2017-06-07 Brandon Alberts , Jack Klys

Motivated by the work of Liu, we study certain canonical quotients of $G_{\emptyset}^T(K)$ -- the Galois group of the maximal unramified extension of a global field $K$ that is split completely at a finite nonempty set of places in $T$ --…

Number Theory · Mathematics 2026-05-15 Ken Willyard

For an algebraic number field $K$ and a prime number $p$, let $\widetilde{K}/K$ be the maximal multiple $\mathbb{Z}_p$-extension. Greenberg's generalized conjecture (GGC) predicts that the Galois group of the maximal unramified abelian…

Number Theory · Mathematics 2020-02-03 Naoya Takahashi

The goal of this paper is to prove theorems that elucidate the Cohen-Lenstra-Martinet conjectures for the distributions of class groups of number fields, and further the understanding of their implications. We start by giving a simpler…

Number Theory · Mathematics 2020-02-18 Weitong Wang , Melanie Matchett Wood

For any odd prime $p$ and any imaginary quadratic field $K$, the $p$-tower group $G_K$ associated to $K$ is the Galois group over $K$ of the maximal unramified pro-$p$-extension of $K$. This group comes with an action of a finite group…

Number Theory · Mathematics 2025-05-19 Richard Pink , Luca Ángel Rubio

The number F(h) of imaginary quadratic fields with a given class number h is of classical interest: Gauss' class number problem asks for a determination of those fields counted by F(h). The unconditional computation of F(h) for h up to 100…

Number Theory · Mathematics 2015-10-16 Samuel Holmin , Nathan Jones , Pär Kurlberg , Cam McLeman , Kathleen L. Petersen

For a finite abelian 2-group $G$, we study the frequency with which quadratic imaginary number fields $K$ have 2-part of their class group $K$ isomorphic to $G$. A philosophy enunciated by Gerth extends the Cohen-Lenstra heuristics for…

Number Theory · Mathematics 2019-02-05 Nathan Jones , Cam McLeman

Let $f\left(K\right)$ be the number of unramified extensions $L/K$ of a quadratic number field $K$ with $\mathrm{Gal}\left(L/K\right)=H$ and $\mathrm{Gal}\left(L/\mathbb{Q}\right)=G$ where $G$ is a central extension of $\mathbb{F}_{2}^{n}$…

Number Theory · Mathematics 2019-07-29 Jack Klys

We provide an infinite family of quadratic number fields with everywhere unramified Galois extensions of Galois group $SL_2(7)$. To my knowledge, this is the first instance of infinitely many such realizations for a perfect group which is…

Number Theory · Mathematics 2025-02-17 Joachim König

Let $G$ be a Frobenius group with an abelian Frobenius kernel $F$ and let $k$ be a finite extension of $\mathbb{Q}$. We obtain an upper bound for the number of degree $|F|$ algebraic extensions $K/k$ with Galois group $G$ with the norm of…

Number Theory · Mathematics 2019-11-04 Harsh Mehta

The main purpose of this paper is to extend results on isomorphism types of the abelianized absolute Galois group $\mathcal G_K^{ab}$, where $K$ denotes imaginary quadratic field. In particular, we will show that if the class number $h_K$…

Number Theory · Mathematics 2017-03-22 Bart de Smit , Pavel Solomatin
‹ Prev 1 2 3 10 Next ›