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Related papers: Height zero characters and Galois automorphisms

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Let $k$ be a finitely generated field of characteristic $p>0$ and $X$ a smooth and proper scheme over $k$. Recent works of Cadoret, Hui and Tamagawa show that, if $X$ satisfies the $\ell$-adic Tate conjecture for divisors for every prime…

Number Theory · Mathematics 2021-05-18 Emiliano Ambrosi

Let k(B_0) and l(B_0) respectively denote the number of ordinary and p-Brauer irreducible characters in the principal block B_0 of a finite group G. We prove that, if k(B_0)-l(B_0)=1, then l(B_0)\geq p-1 or else p=11 and l(B_0)=9. This…

Representation Theory · Mathematics 2021-02-17 Nguyen Ngoc Hung , Benjamin Sambale , Pham Huu Tiep

In this paper, we prove one direction of a conjecture of Navarro-Rizo-Schaeffer Fry-Vallejo positing an algorithm to determine from the character table whether a finite group has $2$-generated Sylow $3$-subgroups. This gives further…

Group Theory · Mathematics 2026-02-17 Eden Ketchum , J. Miquel Martínez , Noelia Rizo , A. A. Schaeffer Fry

The goal of this paper is to obtain lower bounds on the height of an algebraic number in a relative setting, extending previous work of Amoroso and Masser. Specifically, in our first theorem we obtain an effective bound for the height of an…

Number Theory · Mathematics 2017-04-12 Shabnam Akhtari , Kevser Aktaş , Kirsti Biggs , Alia Hamieh , Kathleen Petersen , Lola Thompson

Let p be a prime, B a p-block of a finite group G and b its Brauer correspondent. According to the Alperin-McKay Conjecture, there exists a bijection between the set of irreducible ordinary characters of height zero of B and those of b. In…

Representation Theory · Mathematics 2022-12-16 J. Miquel Martìnez , Damiano Rossi

We prove new modularity lifting theorems for p-adic Galois representations in situations where the methods of Wiles and Taylor--Wiles do not apply. Previous generalizations of these methods have been restricted to situations where the…

Number Theory · Mathematics 2017-07-18 Frank Calegari , David Geraghty

We show that the decomposition matrix of a given group $G$ is unitriangular, whenever $G$ has a normal subgroup $N$ such that the decomposition matrix of $N$ is unitriangular, $G/N$ is abelian and certain characters of $N$ extend to their…

Representation Theory · Mathematics 2023-03-01 Zhicheng Feng , Britta Späth

We complete the proof of Brauer's Height Zero Conjecture from 1955 by establishing the open implication for all odd primes.

Representation Theory · Mathematics 2024-05-06 Gunter Malle , Gabriel Navarro , Amanda A. Schaeffer Fry , Pham Huu Tiep

In this paper, we establish lower bounds on Weil height of algebraic integers in terms of the low lying zeros of the Dedekind zeta-function. As a result, we prove Lehmer's conjecture for certain infinite non-Galois extensions conditional on…

Number Theory · Mathematics 2023-09-29 Anup B. Dixit , Sushant Kala

In 2005 Wolfgang Willems put forward a conjecture proposing a lower bound for the sum of squares of the degrees of the irreducible $p$-Brauer characters of a finite group $G$. We prove this conjecture for the prime $p=2$. For this we rely…

Representation Theory · Mathematics 2020-12-17 Gunter Malle

Let p > 2 be prime. We state and prove (under mild hypotheses on the residual representation) a geometric refinement of the Breuil-M\'ezard conjecture for 2-dimensional mod p representations of the absolute Galois group of Qp. We also state…

Number Theory · Mathematics 2013-03-21 Matthew Emerton , Toby Gee

Let $E$ be a field, $p$ a prime number and $F/E$ a finitely-generated extension of transcendency degree $t$. This paper shows that if the absolute Galois group $\mathcal{G}_{E}$ is of nonzero cohomological $p$-dimension cd$_{p}(E)$, then…

Rings and Algebras · Mathematics 2015-02-10 I. D. Chipchakov

Let p be an odd prime and let L/k be a Galois extension of number fields whose Galois group is isomorphic to the dihedral group of order 2p. Let S be a finite set of primes of L which is stable under the action of Gal(L/k). The Lichtenbaum…

Number Theory · Mathematics 2010-04-21 Luca Caputo

In this paper we study deformations of mod $p$ Galois representations $\tau$ (over an imaginary quadratic field $F$) of dimension $2$ whose semi-simplification is the direct sum of two characters $\tau_1$ and $\tau_2$. As opposed to our…

Number Theory · Mathematics 2016-06-22 Tobias Berger , Krzysztof Klosin

Problem 21 of Brauer's list of problems from 1963 asks whether for any positive integer k there are finitely many isomorphism classes of groups that occur as the defect group of a block with k irreducible characters. We solve this problem…

Group Theory · Mathematics 2023-10-03 Alexander Moretó , Noelia Rizo , A. A. Schaeffer Fry

The classical It\^{o}-Michler theorem states that the degree of every ordinary irreducible character of a finite group $G$ is coprime to a prime $p$ if and only if the Sylow $p$-subgroups of $G$ are abelian and normal. In an earlier paper,…

Group Theory · Mathematics 2019-04-09 Nguyen Ngoc Hung , Pham Huu Tiep

Suppose that $B$ is a Brauer $p$-block of a finite group $G$ with a unique modular character $\varphi$. We prove that $\varphi$ is liftable to an ordinary character of $G$ (which moreover is $p$-rational for odd $p$). This confirms the…

Representation Theory · Mathematics 2015-09-29 Gunter Malle , Gabriel Navarro , Britta Späth

In this paper we compute the Galois cohomology of the pro-p completion of primitive link groups. Here, a primitive link group is the fundamental group of a tame link in the 3-sphere whose linking number diagram is irreducible modulo p (e.g.…

Group Theory · Mathematics 2008-12-08 Inga Blomer , Peter Linnell , Thomas Schick

We investigate a beautiful conjecture of T. Wilde on character values and element orders of finite groups. We reduce it to a statement on nearly simple groups that can be checked ``prime by prime". For these groups, we show that a strong…

Representation Theory · Mathematics 2026-05-07 Gunter Malle , Gabriel Navarro , Pham Huu Tiep

Let $p\geq 5$ be a prime number, $\mathbb{F}$ a finite field of characteristic $p$ and let $\bar{\chi}$ be the mod-$p$ cyclotomic character. Let $\bar{\rho}:\operatorname{G}_{\mathbb{Q}}\rightarrow \operatorname{GL}_2(\mathbb{F})$ be a…

Number Theory · Mathematics 2022-02-24 Anwesh Ray