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For a prime $p$, we determine a Sylow $p$-subgroup $D$ of a finite group $G$ such that the principal $p$-block $B$ of $G$ has four irreducible ordinary characters. It has been determined already for the cases where the number is up to three…

Representation Theory · Mathematics 2021-08-25 Shigeo Koshitani , Taro Sakurai

A new conjecture on characters of finite groups, related to the McKay conjecture, was proposed recently by the first and third authors. In this paper, we prove it for $p$-solvable groups when $p$ is odd.

Representation Theory · Mathematics 2025-06-16 Alexander Moretó , Gabriel Navarro , Noelia Rizo

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 proof of the inductive McKay condition has been shown to imply that the character theory above the characters of degree not divisible by $p$ of a normal subgroup is locally determined. In this note, we establish a similar result for the…

Group Theory · Mathematics 2026-02-16 Asier Arranz

The so-called "local-global" conjectures in the representation theory of finite groups relate the representation theory of $G$ to that of certain proper subgroups, such as the normalizers of particular $p$-groups. Recent results by several…

Group Theory · Mathematics 2013-06-27 Amanda A. Schaeffer Fry

Conjecture A of \cite{EM14} predicts the equality between the smallest positive height of the irreducible characters in a $p$-block of a finite group and the smallest positive height of the irreducible characters in its defect group. Hence,…

Representation Theory · Mathematics 2024-02-06 Gunter Malle , Alexander Moretó , Noelia Rizo

The longstanding Alperin weight conjecture and its blockwise version have been reduced to simple groups recently by Navarro, Tiep, Spaeth and Koshitani. Thus, to prove this conjecture, it suffices to verify the corresponding inductive…

Representation Theory · Mathematics 2019-01-23 Conghui Li

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

We develop the local-global theory of blocks for profinite groups. Given a field $k$ of characteristic $p$ and a profinite group $G$, one may express the completed group algebra $k[[G]]$ as a product $\prod_{i\in I}B_i$ of closed…

Representation Theory · Mathematics 2021-10-11 Ricardo J. Franquiz Flores , John W. MacQuarrie

The Algebraic Dichotomy Conjecture states that the Constraint Satisfaction Problem over a fixed template is solvable in polynomial time if the algebra of polymorphisms associated to the template lies in a Taylor variety, and is NP-complete…

Logic in Computer Science · Computer Science 2015-07-01 Libor Barto , Marcin Kozik

Recently, G. Navarro introduced a new conjecture that unifies the Alperin Weight Conjecture and the Glauberman correspondence into a single statement. In this paper, we reduce this problem to simple groups and prove it for several classes…

Representation Theory · Mathematics 2026-02-18 J. Miquel Martínez , N. Rizo , D. Rossi

By generalizing Frobenius' polynomial method to good partition algebra, we will develop new character theories for a finite group $G$. A uniform defining equations are derived for these kinds of character theories. The new character…

Representation Theory · Mathematics 2023-06-05 Lizhong Wang , Jiping Zhang

The Alperin-McKay conjecture relates height zero characters of an $\ell$-block with the ones of its Brauer correspondent. This conjecture has been reduced to the so-called inductive Alperin-McKay conditions about quasi-simple groups by the…

Representation Theory · Mathematics 2020-08-25 Marc Cabanes , A. A. Schaeffer Fry , Britta Späth

We characterize when a finite group G possesses a Sylow 3-subgroup P with abelianization of order 9 in terms of the number of height zero characters lying in the principal 3-block of G, settling a conjecture put forward by Navarro, Sambale,…

Group Theory · Mathematics 2024-07-16 Eugenio Giannelli , Noelia Rizo , A. A. Schaeffer Fry , Carolina Vallejo

Let $k$ be an algebraically closed field of positive characteristic $p$ and let $\mathbb{F}$ be an algebraically closed field of characteristic 0. We consider Alperin's weight conjecture (over $k$) from the point of view of (stable)…

Representation Theory · Mathematics 2025-07-29 Robert Boltje , Serge Bouc , Deniz Yılmaz

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

Let G be an almost simple, simply connected algebraic group over an algebraically closed field of characteristic p>0. In this paper we restate our conjecture from 1979 on the characters of irreducible modular representations of G so that it…

Representation Theory · Mathematics 2014-08-19 G. Lusztig

Dade's conjecture predicts that if p is a prime, then the number of irreducible characters of a finite group of a given p-defect is determined by local subgroups. In this paper we replace $p$ by a set of primes pi and prove a pi-version of…

Representation Theory · Mathematics 2021-09-24 Gabriel Navarro , Benjamin Sambale

In [7], G. Navarro proposed a refinement of the McKay conjecture involving a special class of Galois automorphisms. In [6] this new conjecture was verified by the author for the alternating groups A(n) when p=2. In this note the Navarro…

Representation Theory · Mathematics 2010-08-18 Rishi Nath

We consider the generalized character $\Psi_{1,p,G}$ of a finite group $G$ which vanishes on all $p$-singular elements of $G$ and whose value at each $p$-regular $y \in G$ is the number of $p$-elements of $C_{G}(y)$. We conjecture that this…

Representation Theory · Mathematics 2025-10-22 Geoffrey R. Robinson