Unsolved Problems

Showing 51-100 of 155 problems (Page 2 of 4)

KOU-21.51
Open

Kourovka Notebook Problem 21.51

Let $p$ be a prime, and $P$ a finite $p$-group. (a) Suppose that $P$ has an abelian subgroup of order $p^n$. For which $n$ does $P$ necessarily have ...

L2
Group Theory
KOU-21.52
Open

Kourovka Notebook Problem 21.52

Let $L$ be a finite non-abelian simple group, and let $D$ be a conjugacy class of involutions in $L$. Consider the complete graph $\Gamma$ with vertex...

L2
Group Theory
KOU-21.53
Open

Kourovka Notebook Problem 21.53

In the notation of 21.52, let $\operatorname{Aut}_t(\Gamma)$ be the set of permutations $\tau\in S_D$ such that $(a,b)\sim(a^\tau,b^\tau)$ whenever $|...

L2
Group Theory
KOU-21.54
Open

Kourovka Notebook Problem 21.54

Let $G$ be a finite soluble group with triality, which means that $G$ admits a group of automorphisms $S$ isomorphic to the symmetric group of degree ...

L2
Group Theory
KOU-21.55
Open

Kourovka Notebook Problem 21.55

Let $q$ be a power of a prime $p$, and let $m_n(q)$ be the maximum $p$-length of $p$-solvable subgroups of $\operatorname{GL}(n,q)$. Is it true that $...

L2
Group Theory
KOU-21.56
Open

Kourovka Notebook Problem 21.56

Let $\ell(X)$ denote the composition length of a finite group $X$. Let $A$ be a finite nilpotent group acting by automorphisms on a finite soluble gro...

L3
Group Theory
KOU-21.57
Open

Kourovka Notebook Problem 21.57

Let X be a non-empty class of finite groups of odd order closed under taking subgroups, homomorphic images, and extensions. Let H be an X-maximal subg...

L2
Group Theory
KOU-21.58
Solved

Kourovka Notebook Problem 21.58

We say that a product $XY=\{xy\mid x\in X,\ y\in Y\}$ of two subsets $X,Y$ of a group $G$ is direct if for every $z\in XY$ there are unique $x\in X$, ...

L2
Group Theory
KOU-21.59
Open

Kourovka Notebook Problem 21.59

For a finite group $G$, let $\chi_1(G)$ denote the totality of the degrees of all irreducible complex characters of $G$ with allowance for their multi...

L2
Group Theory
KOU-21.60
Open

Kourovka Notebook Problem 21.60

Let $G$ be a finite group, $\mathbb Z_{(p)}$ the localization at $p$, and $\mathbb F_p$ the field of $p$ elements. Let $\mathcal X$ be the class of $\...

L2
Group Theory
KOU-21.61
Open

Kourovka Notebook Problem 21.61

For a fixed (finitely generated free)-by-cyclic group $G=F_n\rtimes\mathbb Z$, is there an algorithm that, given a finite subset $S$ of $G$, finds a f...

L2
Group Theory
KOU-21.62
Open

Kourovka Notebook Problem 21.62

Is the uniform subgroup membership problem decidable for (finitely generated free)-by-cyclic groups? That is, for a fixed group $G=F_n\rtimes\mathbb Z...

L2
Group Theory
KOU-21.63
Open

Kourovka Notebook Problem 21.63

Let $F$ be a field of characteristic $p>0$, and let $\Gamma$ be the principal congruence subgroup of $\operatorname{Aut}(F[x_1,\ldots,x_n])$ consistin...

L2
Group Theory
KOU-21.64
Open

Kourovka Notebook Problem 21.64

Is it true that if a normal subgroup $A$ of a Sylow $p$-subgroup of a $p$-soluble finite group $G$ has exponent $p^e$, then the normal closure of $A$ ...

L2
Group Theory
KOU-21.65
Open

Kourovka Notebook Problem 21.65

Suppose that $\phi$ is an automorphism of a finite soluble group $G$. Must $G$ contain a subgroup of index bounded in terms of $|\phi|$ and $|C_G(\phi...

L2
Group Theory
KOU-21.66
Open

Kourovka Notebook Problem 21.66

Suppose that A is a nilpotent group of automorphisms of a finite soluble group G. Is the Fitting height of G bounded in terms of |A| and |CG(A)|? Isa...

L2
Group Theory
KOU-21.67
Open

Kourovka Notebook Problem 21.67

Suppose that $\phi$ is an automorphism of a finite soluble group $G$, and let $r$ be the (Pr\"ufer) rank of the fixed-point subgroup $C_G(\phi)$. Is t...

L2
Group Theory
KOU-21.68
Open

Kourovka Notebook Problem 21.68

A finite group $G$ is said to be semi-abelian if it has a sequence of subgroups $1=G_0\leqslant G_1\leqslant\cdots\leqslant G_n=G$ such that for every...

L3
Group Theory
KOU-21.69
Open

Kourovka Notebook Problem 21.69

Is there an algorithm deciding if a given one-relator group is hyperbolic?...

L2
Group Theory
KOU-21.70
Open

Kourovka Notebook Problem 21.70

A group $G$ is called an orientable Poincar\'e duality group of dimension $n$ over a ring $R$ if it is of type $FP$ over $R$ and $H^i(G;RG)=0$ for $i\...

L2
Group Theory
KOU-21.71
Open

Kourovka Notebook Problem 21.71

For a ring $R$, we say that a group $G$ is of type $FL(R)$ if the trivial $RG$-module $R$ admits a finite resolution by finitely generated free module...

L2
Group Theory
KOU-21.72
Open

Kourovka Notebook Problem 21.72

We say that a group is a Tarski monster if it is finitely generated, not cyclic, and all of its proper non-trivial subgroups are isomorphic to each ot...

L2
Group Theory
KOU-21.73
Open

Kourovka Notebook Problem 21.73

Is the conjugacy problem in $\operatorname{CT}(\mathbb Z)$ algorithmically decidable?...

L2
Group Theory
KOU-21.74
Open

Kourovka Notebook Problem 21.74

Is it algorithmically decidable whether a given element $g\in\operatorname{CT}(\mathbb Z)$ (a) permutes a nontrivial partition of $\mathbb Z$ into re...

L2
Group Theory
KOU-21.75
Open

Kourovka Notebook Problem 21.75

Given two distinct sets $P_1$ and $P_2$ of odd primes none of which is a subset of the other, is it true that $\langle \operatorname{CT}_{P_1}(\mathbb...

L2
Group Theory
KOU-21.76
Open

Kourovka Notebook Problem 21.76

Let $\sigma=(\sigma_{ij})$, $1\leqslant i\ne j\leqslant n$, be an irreducible elementary net (carpet) of order $n\geqslant 3$ over a field $K$ (see 19...

L2
Group Theory
KOU-21.77
Open

Kourovka Notebook Problem 21.77

Let $d$ be an integer that is not divisible by $n$-th powers of primes, let $x^n-d$ be an irreducible polynomial over $\mathbb Q$, let $\theta=\sqrt[n...

L2
Group Theory
KOU-21.78
Open

Kourovka Notebook Problem 21.78

Let $p$ be a prime and let $G$ be a pro-$p$ group. Suppose that all of the (continuous Galois) cohomology groups $H^n(G,\mathbb F_p)$ of $G$ with coef...

L2
Group Theory
KOU-21.79
Open

Kourovka Notebook Problem 21.79

Let $G$ be a finitely generated group with a fixed finite generating set $S$ and the corresponding word metric $L_S(*)$. An element $g$ is said to be ...

L2
Group Theory
KOU-21.80
Open

Kourovka Notebook Problem 21.80

Do there exist finitely generated left-orderable groups with only one nontrivial conjugacy class?...

L2
Group Theory
KOU-21.81
Open

Kourovka Notebook Problem 21.81

Let $\Gamma$ be a finite simple group and let $N_n(\Gamma)$ denote the set of normal subgroups of the free group $F_n$ of rank $n$ whose quotient is i...

L3
Group Theory
KOU-21.82
Open

Kourovka Notebook Problem 21.82

Conjecture: For $n\geqslant 3$, there are no finite simple characteristic quotients of the free group $F_n$....

L3
Group Theory
KOU-21.83
Open

Kourovka Notebook Problem 21.83

Conjecture: Metabelian groups are permutation-stable....

L3
Group Theory
KOU-21.84
Open

Kourovka Notebook Problem 21.84

For $\sigma\in S_n$ and $\tau\in S_m$, where $n\leqslant m$, let $d_n^{\mathrm{flex}}(\sigma,\tau)=(1/n)\cdot(|\{x\in\{1,\ldots,n\}\mid \sigma(x)\ne\t...

L2
Group Theory
KOU-21.85
Open

Kourovka Notebook Problem 21.85

Is a flexibly permutation-stable group always permutation-stable?...

L2
Group Theory
KOU-21.86
Open

Kourovka Notebook Problem 21.86

A group $G$ is said to be sofic if for every finite set $F\subseteq G$ containing $1$ and every $\varepsilon>0$ there exist $n\in\mathbb N$ and a map ...

L3
Group Theory
KOU-21.87
Open

Kourovka Notebook Problem 21.87

Assume that a finite group G has a family of d-generator subgroups whose indices have no common divisor. Is it true that G can be generated by d+1 ele...

L2
Group Theory
KOU-21.88
Open

Kourovka Notebook Problem 21.88

Is there a finite non-abelian group $G$ of odd order, with $k(G)$ conjugacy classes, such that $k(G)/|G|=1/17$?...

L2
Group Theory
KOU-21.89
Open

Kourovka Notebook Problem 21.89

For $n>39$, is it true that the number of conjugacy classes in the symmetric group $S_n$ of degree $n$ is never a divisor of the order of $S_n$? In ot...

L2
Group Theory
KOU-21.90
Open

Kourovka Notebook Problem 21.90

Let $\Gamma$ be a graph of diameter $d$. For $i\in\{1,2,\ldots,d\}$, let $\Gamma_i$ be the graph on the same vertex set as $\Gamma$ with vertices $u,w...

L2
Group Theory
KOU-21.91
Open

Kourovka Notebook Problem 21.91

Conjecture: The sum of squares of the degrees of the irreducible $p$-Brauer characters of a finite group $G$ is at least the $p'$-part of $|G|$....

L3
Group Theory
KOU-21.92
Open

Kourovka Notebook Problem 21.92

Conjecture: The number of irreducible $p$-Brauer characters of a finite group $G$ is bounded above by the maximum of the number of conjugacy classes $...

L3
Group Theory
KOU-21.93
Open

Kourovka Notebook Problem 21.93

Let $G$ be a group and let $k\geqslant 2$. Let $H_1,\ldots,H_k$ be subgroups of $G$, and $g_1,\ldots,g_k$ elements of $G$ such that the cosets $g_1H_1...

L2
Group Theory
KOU-21.94
Open

Kourovka Notebook Problem 21.94

The Gruenberg--Kegel graph (or the prime graph) GK(G) of a finite group G is a labelled graph with vertex set consisting of all prime divisors of the ...

L2
Group Theory
KOU-21.95
Open

Kourovka Notebook Problem 21.95

Is there an almost simple but not simple group which is recognizable by the isomorphism type of its Gruenberg--Kegel graph?...

L2
Group Theory
KOU-21.96
Open

Kourovka Notebook Problem 21.96

Is it true that a periodic group containing an involution is locally finite if the centralizer of every element of even order is locally finite?...

L2
Group Theory
KOU-21.97
Open

Kourovka Notebook Problem 21.97

Is it true that for every positive rational number $r$ there exists a finite group $G$ such that $|\operatorname{Aut}(G)|/|G|=r$?...

L2
Group Theory
KOU-21.98
Open

Kourovka Notebook Problem 21.98

Let w be a multilinear commutator word, and assume that G is a group where the set of w-values is covered by finitely many cyclic subgroups. Is it tru...

L2
Group Theory
KOU-21.99
Open

Kourovka Notebook Problem 21.99

Conjecture: If $G$ is a transitive permutation group on a finite set $\Omega$, then for any distinct $\alpha,\beta\in\Omega$ there is an element $g\in...

L3
Group Theory
KOU-21.100
Open

Kourovka Notebook Problem 21.100

Suppose that $A$ and $G$ are finite groups such that $A$ acts coprimely on $G$ by automorphisms. Let $C=C_G(A)$ be the fixed-point subgroup, and let $...

L2
Group Theory