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Let G be a finite group of order n and V an irreducible representation over the complex numbers of dimension d. For some nonnegative number e, we have n=d(d+e). If e is small, then the character of V has unusually large degree. We fix e and…

Group Theory · Mathematics 2008-08-28 Noah Snyder

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 prove that the number of irreducible ordinary characters in the principal $p$-block of a finite group $G$ of order divisible by $p$ is always at least $2\sqrt{p-1}$. This confirms a conjecture of H\'{e}thelyi and K\"{u}lshammer for…

Representation Theory · Mathematics 2023-05-31 Nguyen Ngoc Hung , A. A. Schaeffer Fry

There has been some interest on how the average character degree affects the structure of a finite group. We define, and denote by $ \mathrm{anz}(G) $, the average number of zeros of characters of a finite group $ G $ as the number of zeros…

Group Theory · Mathematics 2021-06-30 Sesuai Y. Madanha

The codegree ${\rm codeg}(\mathcal{P})$ of a lattice polytope $\mathcal{P}$ is a fundamental invariant in discrete geometry. In the present paper, we investigate the codegree of the stable set polytope $\mathcal{P}_G$ associated with a…

Combinatorics · Mathematics 2026-04-01 Koji Matsushita , Akiyoshi Tsuchiya

Let K be a valued field of characteristic p>0 with non-p-divisible value group. We show that every finite embedding problem for K whose kernel is a p-group is properly solvable.

Algebraic Geometry · Mathematics 2010-08-12 Lior Bary-Soroker , Nguyen Duy Tan

Let G be a finite group and let Irr(G) be the set of all irreducible complex characters of G. Let cd(G) be the set of all character degrees of G and denote by \rho(G) the set of primes which divide some character degrees of G. The prime…

Group Theory · Mathematics 2013-08-27 Hung P. Tong-Viet

Let $G$ be a finite group and let $\pi(G)=\{p_1, p_2, \ldots, p_k\}$ be the set of prime divisors of $|G|$ for which $p_1<p_2<\cdots<p_k$. The Gruenberg-Kegel graph of $G$, denoted ${\rm GK}(G)$, is defined as follows: its vertex set is…

Group Theory · Mathematics 2017-05-16 A. Mohammadzadeh , A. R. Moghaddamfar

If $G$ is a finite group, an irreducible complex-valued character $\chi$ is called rational if $\chi(g)$ is rational for all $g\in G$. Also, a conjugacy class $x^G$ is called rational, if for all irreducible complex-valued character $\chi$,…

Group Theory · Mathematics 2025-03-27 Dilpreet Kaur , Saikat Panja

Let $p$ be a prime and let $G$ be a finite group such that the smallest prime that divides $|G|$ is $p$. We find sharp bounds, depending on $p$, for the commuting probability and the average character degree to guarantee that $G$ is…

Group Theory · Mathematics 2023-08-21 Juan Martínez

We present a description of non-solvable groups in which all real irreducible character degrees are prime-power numbers.

Group Theory · Mathematics 2021-07-02 Lorenzo Bonazzi

Let $\bbk$ be an algebraically closed field of prime characteristic $p$. If $p$ does not divide $n$, irreducible modules over $\frak {sl}_n$ for regular and subregular nilpotent representations have already known(see \cite{Jan2} and…

Representation Theory · Mathematics 2021-10-15 Bin Liu , Bin Shu , Xin Wen

The weights for a finite group G with respect to a prime number p where introduced by Jon Alperin, in order to formulate his celebrated conjecture. In 1992, Everett Dade formulates a refinement of Alperin's conjecture involving ordinary…

Group Theory · Mathematics 2010-06-29 Lluis Puig

The Fong-Swan theorem shows that for a $p$-solvable group $G$ and Brauer character $\phi \in \ibrg$, there is an ordinary character $\chi \in \irrg$ such that $\chi^0 = \phi$, where $^0$ denotes restriction to the $p$-regular elements of…

Group Theory · Mathematics 2007-05-23 James P. Cossey

we obtain a necessary condition for the character degree graph with all of its vertices are odd degree of a finite solvable group G.

Group Theory · Mathematics 2023-05-23 G. Sivanesan , C. Selvaraj

Let $G$ be a finite group and $\chi\in \irr(G)$. The codegree of $\chi$ is defined as $\cod(\chi)=\frac{|G:\ker(\chi)|}{\chi(1)}$ and $\cod(G)=\{\cod(\chi) \ |\ \chi\in \irr(G)\}$ is called the set of codegrees of $G$. In this paper, we…

Group Theory · Mathematics 2022-09-07 Yang Liu , Yong Yang

Let $G$ be a finite group and ${\rm cd}(G)$ denote the set of complex irreducible character degrees of $G$. In this paper, we prove that if $G$ is a finite group and $H$ is an almost simple group with socle $H_{0}= \, ^{2}{\rm G}_{2}(q)$,…

Group Theory · Mathematics 2023-03-08 Seyed Hassan Alavi

In this paper, we get the sharp bound for $|G/O_p(G)|_p$ under the assumption that either $p^2 \nmid \chi(1)$ for all $\chi \in {\rm Irr}(G)$ or $p^2 \nmid \phi(1)$ for all $\phi \in {\rm IBr}_p(G)$. This would settle two conjectures raised…

Group Theory · Mathematics 2021-02-19 Guohua Qian , Yong Yang

For any finite group $G$, Thompson proved that, for each $\chi\in {\rm Irr}(G)$, $\chi(g)$ is a root of unity or zero for more than a third of the elements $g\in G$, and Gallagher proved that, for each larger than average class $g^G$,…

Group Theory · Mathematics 2022-08-23 Alexander R. Miller

Let $G$ be a finite group. For a prime $p$ and an integer $e \geq 0$, we denote by $\Gamma_{p,e}(G)$ the set of all pairs $(H, \varphi)$, where $H$ is a $p$-subgroup of $G$ of order greater than $p^e$ and $\varphi$ is a complex irreducible…

Group Theory · Mathematics 2025-12-30 Hangyang Meng , Yuting Yang