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Geoff Robinson

United Kingdom

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Top Questions
Top Answers
81
Is it true that $0.999999999\ldots=1$?
math.stackexchange.com

65
Why can't a nonabelian group be 75% abelian?
mathoverflow.net

59
The identity cannot be a commutator in a Banach algebra?
math.stackexchange.com

49
Why is the complex number $z=a+bi$ equivalent to the matrix form $\left(\begin{smallmatrix}a &-b\\b&a\end{smallmatrix}\right)$
math.stackexchange.com

42
How large can the smallest generating set of a group $G$ of order $n$ be?
mathoverflow.net

36
Properties to have matrices that commute in $\mathrm{GL}_n(\mathbb C)$
mathoverflow.net

35
Determinant of sum of positive definite matrices
mathoverflow.net

29
How to prove that $\mathbb{Q}[\sqrt{p_1}, \sqrt{p_2}, \ldots,\sqrt{p_n} ] = \mathbb{Q}[\sqrt{p_1}+ \sqrt{p_2}+\cdots + \sqrt{p_n}]$, for $p_i$ prime?
math.stackexchange.com

27
Groups that do not exist
mathoverflow.net

26
Character free proof that Frobenius kernel is a normal subgroup?
mathoverflow.net

26
Why is this character expression an integer?
mathoverflow.net

26
Eigenvalues of nonnegative integer matrices
mathoverflow.net

26
In what sense is SL(2,q) "very far from abelian"?
mathoverflow.net

26
On permanents and determinants of finite groups
mathoverflow.net

25
Is each squared finite group trivial?
mathoverflow.net

24
Number of 2-dimensional irreducible representations of a finite group ?
mathoverflow.net

23
Atypical use of Sylow?
mathoverflow.net

23
How much of character theory can be done without Schur's lemma or the Artin-Wedderburn theorem?
mathoverflow.net

23
General bound for the number of subgroups of a finite group
mathoverflow.net

22
Subgroups of GL(2,q)
mathoverflow.net

22
Failure of a basic fact from Representation Theory
mathoverflow.net

22
Prominent non-mathematical work of mathematicians
mathoverflow.net

21
How is a group made up of simple groups?
math.stackexchange.com

21
Number of involutions in a finite group
mathoverflow.net

20
When does $G\times G\times G$ admit a faithful group action on a set of size $|G|$?
mathoverflow.net

20
Does the symmetric group $S_{10}$ factor as a knit product of symmetric subgroups $S_6$ and $S_7$?
mathoverflow.net

20
5/8 bound in group theory
mathoverflow.net

20
What is the standard 2-generating set of the symmetric group good for?
mathoverflow.net

20
On the finite simple groups with an irreducible complex representation of a given dimension
mathoverflow.net

20
What are the connections between pi and prime numbers?
mathoverflow.net

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