English
Related papers

Related papers: Groups with exactly two supercharacter theories

200 papers

We investigate the "two-parameter" quantum symmetry groups that we previously constructed with Skalski, with the conclusion that some of these quantum groups, namely those without singletons, are "super-easy" in a suitable sense, that we…

Quantum Algebra · Mathematics 2018-04-06 Teodor Banica

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

A remarkable result of Thompson states that a finite group is soluble if and only if its two-generated subgroups are soluble. This result has been generalized in numerous ways, and it is in the core of a wide area of research in the theory…

Group Theory · Mathematics 2019-08-12 P. Hauck , L. S. Kazarin , A. Martínez-Pastor , M. D. Pérez-Ramos

Cameron, Manna and Mehatari investigated the question of which finite groups admit a power graph that is a cograph, also called power-cograph groups (Journal of Algebra 591 (2022)). They give a classification for nilpotent groups and…

Group Theory · Mathematics 2022-07-26 Jendrik Brachter , Eda Kaja

An irreducible character of a finite group $G$ is called quasi $p$-Steinberg character for a prime $p$ if it takes a nonzero value on every $p$-regular element of $G$. In this article, we classify the quasi $p$-Steinberg characters of…

Representation Theory · Mathematics 2021-03-11 Digjoy Paul , Pooja Singla

We provide non-isomorphic finite 2-groups which have isomorphic group algebras over any field of characteristic 2, thus settling the Modular Isomorphism Problem.

Rings and Algebras · Mathematics 2021-12-16 Diego García , Leo Margolis , Ángel del Río

Let N be a minimal normal nonabelian subgroup of a finite group G. We will show that there exists a nontrivial irreducible character of N of degree at least 5 which is extendible to G. This result will be used to settle two open questions…

Group Theory · Mathematics 2010-04-16 Kay Magaard , Hung P. Tong-Viet

We introduce the class of unshreddable theories, which contains the simple and NIP theories, and prove that such theories have exactly saturated models in singular cardinals, satisfying certain set-theoretic hypotheses. We also give…

Logic · Mathematics 2021-04-19 Itay Kaplan , Nicholas Ramsey , Saharon Shelah

Let $T$ be a (first order complete) dependent theory, ${\mathfrak{C}}$ a $\bar\kappa$-saturated model of $T$ and $G$ a definable subgroup which is abelian. Among subgroups of bounded index which are the union of $<\bar\kappa$ type definable…

Logic · Mathematics 2021-09-15 Saharon Shelah

We show that for n>=3 the symplectic group Sp(n) is as a 2-compact group determined up to isomorphism by the isomorphism type of its maximal torus normalizer. This allows us to determine the integral homotopy type of Sp(n) among connected…

Algebraic Topology · Mathematics 2018-08-08 A. Vavpetic , A. Viruel

In this paper we create many examples of hyperbolic groups with subgroups satisfying interesting finiteness properties. We give the first examples of subgroups of hyperbolic groups which are of type $FP_2$ but not finitely presented. We…

Group Theory · Mathematics 2021-01-08 Robert Kropholler , Federico Vigolo

Let $G$ be a finite group. Denote by $\textrm{Irr}(G)$ the set of all irreducible complex characters of $G.$ Let $\textrm{cd}(G)=\{\chi(1)\;|\;\chi\in \textrm{Irr}(G)\}$ be the set of all irreducible complex character degrees of $G$…

Group Theory · Mathematics 2011-02-23 Hung P. Tong-Viet

We construct a solvable group G of order 5648590729620 such that the set of element orders of G coincides with that of the simple group S(4,3). This completes the determination of finite simple groups isospectral to solvable groups.

Group Theory · Mathematics 2012-02-16 Andrei V. Zavarnitsine

The prime graph $\Gamma(G)$ of a finite group $G$ (also known as the Gruenberg-Kegel graph) has as its vertices the prime divisors of $|G|$, and $p\text-q$ is an edge in $\Gamma(G)$ if and only if $G$ has an element of order $pq$. Since…

Group Theory · Mathematics 2022-11-30 Ziyu Huang , Thomas Michael Keller , Shane Kissinger , Wen Plotnick , Maya Roma , Yong Yang

The finite groups having an indecomposable polynomial invariant whose degree is at least half of the order of the group are classified. Apart from four sporadic exceptions these are exactly the groups having a cyclic subgroup of index at…

Representation Theory · Mathematics 2013-12-31 K. Cziszter , M. Domokos

We construct uncountably many infinite characters of type II for $SL_n(\mathbb{Z})$, $n \geq 2$.

Operator Algebras · Mathematics 2021-12-21 Rémi Boutonnet

Let $k(G)$ be the number of conjugacy classes of finite groups $G$ and $\pi_e(G)$ be the set of the orders of elements in $G$. Then there exists a non-negative integer $k$ such that $k(G)=|\pi_e(G)|+k$. We call such groups to be $co(k)$…

Group Theory · Mathematics 2007-05-23 Xianglin Du , Wujie Shi

We prove the conjugacy of Sylow $p$-subgroups of linear pseudofinite groups under the assumption of the existence of a finite Sylow $p$-subgroup. We also give an example of a linear pseudofinite group with non-conjugate Sylow $2$-subgroups.

Group Theory · Mathematics 2023-04-18 Pınar Uğurlu

The question of whether there exists a finite group of order at least three in which every element except one is a commutator has remained unresolved in group theory. In this article, we address this open problem by developing an…

Group Theory · Mathematics 2026-01-01 Omar Hatem , Daoud Siniora

An irredundant cover of a finite group $G$ is a collection of proper subgroups whose union is $G$ and which contains no smaller subcover. We classify finite groups which possess exactly two irredundant covers, thereby initiating an answer…

Group Theory · Mathematics 2022-06-22 Jonathan Cohen , Kyle Rosengartner