Linked Questions
10 questions linked to/from The finite subgroups of SU(n)
2
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Finite subgroups of compact simple Lie groups [duplicate]
The finite subgroups of $SU(2)$ consist of the symmetry groups of the Platonic solids plus the finite subgroups of $O(2)$. I would like to know if there are any results concerning $SU(3)$. In ...
10
votes
1
answer
1k
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Model theory of the complex numbers with conjugation
Do there exist some results on the theory of $\mathbb{C}$ in the language $\{0,1+, \times, \overline{\cdot}\}$, where $\overline{\cdot}$ is the conjugation map $\overline{a+ib} = a - ib$?
I'm ...
12
votes
1
answer
655
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Which Lie groups have finitely many conjugacy classes of subgroups of fixed isomorphism type?
Let $G$ be a real Lie group.
What conditions must $G$ satisfy so that the following is true:
For any finite group $\Gamma$ there exist finitely many conjugacy classes of subgroups of $G$ that are ...
11
votes
1
answer
357
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Alternating subgroups of $\mathrm{SU}_n $
$\DeclareMathOperator\PSU{PSU}$Let $ \PSU_n $ be the projective unitary group. Let $ A_m $ be the alternating group on $ m $ letters.
$ A_5 $ is a maximal closed subgroup of $ PSU_2 \cong SO_3(\mathbb{...
6
votes
1
answer
567
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Finite simple groups and $ \operatorname{SU}_n $
A follow-up question to Alternating subgroups of $\mathrm{SU}_n $.
$\DeclareMathOperator\PU{PU}\DeclareMathOperator\PSU{PSU}\DeclareMathOperator\PSL{PSL}$Let $ \PU_m $ be the projective unitary group, ...
7
votes
1
answer
548
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The probability that two elements of a finite nonabelian simple group commute
It is mentioned in here (last paragraph of the first page) that Dixon proved the following result: the probability that two elements of a finite nonabelian simple group commute is at most $\frac{1}{12}...
3
votes
2
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326
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Finite subgroups of Spin(9)
I'm trying to classify compact manifolds $M^{16}$ with a metric which is locally conformal to a (local) metric with holonomy (included in) Spin(9)$\subset$SO(16). To do this, I would need a complete ...
2
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1
answer
365
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Self-normalizing implies maximal for subgroup of compact Lie group
Consider the compact group $ G=\operatorname{SO}_3(\mathbb{R}) $. The closed subgroups of $ G $ (other than the trivial group 1 and the whole group $ G $) are exactly $ O_2$, $\operatorname{SO}_2 $ ...
3
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0
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108
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Where can I learn about the discrete symmetries of the complex projective plane (or space)?
I understand that $CP^1$ is the Riemann Sphere. I guess all its discrete symmetries were known for a long time and well-classified. (But suggestions or good references where this is worked out in a ...
4
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The number of uniformly finite subgroups of some Lie groups
Let $G$ be the group $SO(n)$, $SU(n)$ or $Sp(n)$.
Let $F_m$ be the collection of finite subgroups of $G$ such that its order is bounded by $m$. Two elements in $F_m$ are identified if they are ...