User Sean Eberhard

4 votes

A character-free proof that a permutation group is doubly transitive iff the associated permutation module over $\mathbb C$ has irreducible augmentation submodule?

answered Jul 14, 2017 at 22:45

4 votes

Men in a bar - stoch. processes

answered Jan 18, 2012 at 10:18

4 votes

Groups with exponentially growing centre

answered Sep 12, 2019 at 18:31

4 votes

Maximize $f(0)+\cdots+f(n-1)$ subject to $f(x)f(y) + f(x+y) \leq 1$

answered Dec 30, 2018 at 23:02

4 votes

Accepted

A variation of closed-subgroup theorem

answered May 6, 2021 at 21:40

4 votes

Regular subsets of $\text{PSL}(2, q)$

answered May 7, 2021 at 9:23

3 votes

Zero trace elements in finite fields

answered Mar 24, 2022 at 14:50

3 votes

Does asymmetric fraction of finite groups tend to $0$?

answered Oct 7, 2019 at 13:45

3 votes

Multiplicative and additive groups of the field $(\prod_{n\in\omega}\mathbb{Z}/p_n\mathbb{Z})/\simeq_{\cal U}$

answered Jul 24, 2020 at 9:58

3 votes

Accepted

Can $S_n$ be partitioned into subsets containing an involution and satisfying $∀σ≠τ, ∃j$ s.t. $σ(j)≠τ(j),σ^{−1}(j)=τ^{−1}(j)$?

answered Jul 8, 2018 at 5:53

3 votes

Uncountable family of infinite subsets with pairwise finite intersections

answered Feb 26, 2012 at 23:06

3 votes

Accepted

Finite-index iff positive density?

answered Jul 16, 2016 at 13:50

3 votes

Powers of finite simple groups

answered Nov 21, 2014 at 18:47

3 votes

Accepted

Is the transpose of an infinite Hadamard matrix also Hadamard?

answered Sep 13 at 9:54

3 votes

Accepted

Bounding size of group by number of generators, order of elements, and nilpotency class (Restricted Burnside's)

answered May 25, 2023 at 16:31

2 votes

Universal group such that every finite group is a quotient

answered Nov 15, 2023 at 10:38

2 votes

Accepted

Is there anything known about the lower central series of a group $G\wr C_p$?

answered Mar 7, 2023 at 16:24

2 votes

Accepted

Can a positive measure subset of a free group be nowhere dense?

answered Dec 22, 2014 at 15:58

2 votes

Request for examples of 4-regular, non-planar, girth at least 5 graphs

answered Apr 10, 2015 at 12:43

2 votes

fixed points of permutation groups

answered Jun 13, 2017 at 20:16

2 votes

Accepted

Kantor's Singer cycle theorem

answered Jun 25, 2018 at 23:03

2 votes

Simple closed curves and the coefficent of $\exp(i\theta)$ in the associated Fourier series

answered Mar 17, 2012 at 13:55

2 votes

Maximum number of triangles no two of which have a common edge

answered Oct 8, 2018 at 0:40

2 votes

Accepted

What is the simplest known finite presentation of a free nilpotent group?

answered May 3, 2019 at 12:25

2 votes

Algorithm to calculate edge orbits of a graph

answered Feb 18, 2022 at 9:24

2 votes

Is every virtually free group residually finite?

answered Apr 29, 2022 at 13:39

2 votes

Nesterov, 1983 Paper translation from russian to english

answered Jun 15, 2021 at 12:14

2 votes

Accepted

Lower bound of the probability of singular random matrix over $\{\pm1\}$ in ``Singularity of random Bernoulli matrices"

answered Mar 22, 2021 at 9:54

1 vote

Partitions of ${\rm Sym}(\mathbb{N})$ induced by convergent, but not absolutely convergent series

answered Sep 19, 2019 at 17:22

1 vote

Accepted

Schur triples question

answered Jun 14, 2020 at 8:21

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100 Answers

A character-free proof that a permutation group is doubly transitive iff the associated permutation module over $\mathbb C$ has irreducible augmentation submodule?

Men in a bar - stoch. processes

Groups with exponentially growing centre

Maximize $f(0)+\cdots+f(n-1)$ subject to $f(x)f(y) + f(x+y) \leq 1$

A variation of closed-subgroup theorem

Regular subsets of $\text{PSL}(2, q)$

Zero trace elements in finite fields

Does asymmetric fraction of finite groups tend to $0$?

Multiplicative and additive groups of the field $(\prod_{n\in\omega}\mathbb{Z}/p_n\mathbb{Z})/\simeq_{\cal U}$

Can $S_n$ be partitioned into subsets containing an involution and satisfying $∀σ≠τ, ∃j$ s.t. $σ(j)≠τ(j),σ^{−1}(j)=τ^{−1}(j)$?

Uncountable family of infinite subsets with pairwise finite intersections

Finite-index iff positive density?

Powers of finite simple groups

Is the transpose of an infinite Hadamard matrix also Hadamard?

Bounding size of group by number of generators, order of elements, and nilpotency class (Restricted Burnside's)

Universal group such that every finite group is a quotient

Is there anything known about the lower central series of a group $G\wr C_p$?

Can a positive measure subset of a free group be nowhere dense?

Request for examples of 4-regular, non-planar, girth at least 5 graphs

fixed points of permutation groups

Kantor's Singer cycle theorem

Simple closed curves and the coefficent of $\exp(i\theta)$ in the associated Fourier series

Maximum number of triangles no two of which have a common edge

What is the simplest known finite presentation of a free nilpotent group?

Algorithm to calculate edge orbits of a graph

Is every virtually free group residually finite?

Nesterov, 1983 Paper translation from russian to english

Lower bound of the probability of singular random matrix over $\{\pm1\}$ in ``Singularity of random Bernoulli matrices"

Partitions of ${\rm Sym}(\mathbb{N})$ induced by convergent, but not absolutely convergent series

Schur triples question