English
Related papers

Related papers: The Galois action on character tables

200 papers

For every finite field F and every positive integer r, there exists a finite extension F' of F such that either SO(2r+1,F') or its simple derived group can be realized as a Galois group over Q. If the characteristic of F is 3 or 5 (mod 8),…

Number Theory · Mathematics 2008-07-08 Chandrashekhar Khare , Michael Larsen , Gordan Savin

This article is the third and last part of a series of three articles about compatible systems of symplectic Galois representations and applications to the inverse Galois problem. This part proves the following new result for the inverse…

Number Theory · Mathematics 2013-09-24 Sara Arias-de-Reyna , Luis Dieulefait , Sug Woo Shin , Gabor Wiese

In this paper we show that integral fusion categories with rational structure constants admit a natural group of symmetries given by the Galois group of their character tables. We also generalize a well known result of Burnside from…

Quantum Algebra · Mathematics 2020-05-29 Sebastian Burciu

Let a discrete group $G$ act on a unital simple C$^*$-algebra $A$ by outer automorphisms. We establish a Galois correspondence $H\mapsto A\rtimes_{\alpha,r}H$ between subgroups of $G$ and C$^*$-algebras $B$ satisfying $A\subseteq B…

Operator Algebras · Mathematics 2019-02-22 Jan Cameron , Roger R. Smith

Classes of functions of several variables on arbitrary non-empty domains that are closed under permutation of variables and addition of dummy variables are characterized in terms of generalized constraints, and hereby Hellerstein's Galois…

Rings and Algebras · Mathematics 2016-11-22 Erkko Lehtonen

We describe the mapping class group action on the cohomology of the twisted $\mathrm{SL}_n$-character variety of a surface $\Sigma_g$ of genus $g$. Our main tool is a relative version of the endoscopic decomposition of Maulik-Shen; this…

Algebraic Geometry · Mathematics 2026-03-16 Anne Larsen

We construct Galois theory for sublattices of certain complete modular lattices and their automorphism groups. A well-known description of the intermediate subgroups of the general linear group over a semilocal ring containing the group of…

Group Theory · Mathematics 2007-05-23 Alexandre A. Panin

In this note we give a self-contained proof of the following classification (up to conjugation) of subgroups of the general symplectic group of dimension n over a finite field of characteristic l, for l at least 5, which can be derived from…

Number Theory · Mathematics 2014-05-07 Sara Arias-de-Reyna , Luis Dieulefait , Gabor Wiese

The notion of a coalgebra-Galois extension is defined as a natural generalisation of a Hopf-Galois extension. It is shown that any coalgebra-Galois extension induces a unique entwining map $\psi$ compatible with the right coaction. For the…

q-alg · Mathematics 2008-02-03 Tomasz Brzezinski , Piotr M. Hajac

Let $E/\mathbb{Q}$ be an elliptic curve, let $\overline{\mathbb{Q}}$ be a fixed algebraic closure of $\mathbb{Q}$, and let $G_{\mathbb{Q}}=\text{Gal}(\overline{\mathbb{Q}}/\mathbb{Q})$ be the absolute Galois group of $\mathbb{Q}$. The…

Number Theory · Mathematics 2024-06-04 Harris B. Daniels , Álvaro Lozano-Robledo , Jackson S. Morrow

We study the action on the deformation space of a formal group by the maximal finite subgroup $G$ of its automorphisms, at the first height where the group has nontrivial $p$-torsion for odd $p$. We show given this group $G$ there is a…

Algebraic Geometry · Mathematics 2025-09-30 Rin Ray

We establish a Galois correspondence for a minimal action of a compact quantum group ${\mathbb G}$ on a von Neumann factor $M$. This extends the result of Izumi, Longo and Popa who treated the case of a Kac algebra. Namely, there exists a…

Operator Algebras · Mathematics 2008-01-09 Reiji Tomatsu

The Galois group of a parameterized polynomial system of equations encodes the structure of the solutions. This monodromy group acts on the set of solutions for a general set of parameters, that is, on the fiber of a projection from the…

Algebraic Geometry · Mathematics 2021-05-27 Carlos Améndola , Julia Lindberg , Jose Israel Rodriguez

In this note we study the geometry of torsors under flat and finite commutative group schemes of rank p above curves in characteristic p and above relative curves over a complete discrete valuation ring of inequal characteristics. In bothe…

Algebraic Geometry · Mathematics 2007-05-23 Mohamed saidi

In this paper, we prove new instances of the inverse Galois problem over global function fields for finite groups of Lie type. This is done by constructing compatible systems of $\ell$-adic Galois representations valued in a semisimple…

Number Theory · Mathematics 2023-10-25 Shiang Tang

For an arbitrary localic etale groupoid G we provide simple descriptions, in terms of modules over the quantale O(G) of the groupoid, of the continuous actions of G, including actions on open maps and sheaves. The category of G-actions is…

Category Theory · Mathematics 2011-03-29 Pedro Resende

Real forms of a complex reductive group are classified by Galois cohomology H^1(Gamma,G_ad) where G_ad is the adjoint group. Cartan's classification of real forms in terms of maximal compact subgroups can be stated in terms of H^(Z/2Z,G_ad)…

Group Theory · Mathematics 2018-05-23 Jeffrey Adams , Olivier Taïbi

For each finite subgroup $G$ of $PGL_2(\mathbb{Q})$, and for each integer $n$ coprime to $6$, we construct explicitly infinitely many Galois extensions of $\mathbb{Q}$ with group $G$ and whose ideal class group has $n$-rank at least…

Number Theory · Mathematics 2021-11-05 Jean Gillibert , Pierre Gillibert

In this paper, we consider some generalized commutator equations in a finite group and show that the number of solutions of such equations are characters of that group. We also obtain explicit formula for this character, considering the…

Group Theory · Mathematics 2016-05-05 Sunil Kumar Prajapati , Rajat Kanti Nath

In characteristic $0$, symplectic automorphisms of K3 surfaces (i.e.\ automorphisms preserving the global $2$-form) and non-symplectic ones behave differently. In this paper we consider the actions of the group schemes $\mu_{n}$ on K3…

Algebraic Geometry · Mathematics 2023-02-21 Yuya Matsumoto