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A nomadic postdoc, currently in Australia.

Apr
13
asked Topological systems of imprimitivity
Apr
2
comment Should one post a paper on the arXiv if it is not intended to be published?
The novelty threshold for putting something on the arXiv is lower than for a typical journal article. For instance, I would not be surprised to see notes from a postgrad-level study group up there, if the topic was something that has not yet been standardised into textbook form. If it's something that could be useful to research-level mathematicians, then go ahead.
Feb
17
awarded  Yearling
Dec
22
comment Powers in compact coset spaces
Good point about sequential compactness. It looks like a net would work for the $\mathbb{T}^{\mathbb{T}}$ example.
Dec
22
comment Powers in compact coset spaces
If $G$ is t.d.l.c. and $K$ is normal, it reduces to the profinite case, which is indeed easy. I'm wondering what happens if $K$ is not normal.
Dec
22
revised Powers in compact coset spaces
added 15 characters in body
Dec
22
comment Powers in compact coset spaces
Ah yes, I see the issue there if $G$ is not metrisable. Yes, a net is fine.
Dec
22
asked Powers in compact coset spaces
Dec
17
awarded  Good Question
Dec
16
comment What is the universal property of quotienting a normaliser of the subgroup?
In the context of $G$-sets, 'conjugacy class of subgroups' is perhaps a more natural notion than 'subgroup', since conjugacy classes of subgroups naturally correspond to transitive $G$-sets.
Dec
15
comment Why do sporadic simple groups have so few conjugacy classes?
That is interesting. I wonder how much of this is coming from the Weyl group and how much from the Borel subgroup.
Dec
15
comment Why do sporadic simple groups have so few conjugacy classes?
For general groups of Lie type, I would guess that increasing the field size tends to give relatively many conjugacy classes (since it doesn't add any 'non-abelian-ness'), whereas increasing the rank does not, as per Nick Gill's answer.
Dec
15
comment Why do sporadic simple groups have so few conjugacy classes?
Yes, that makes sense as an invariant. I suppose it is only some of the sporadics that stand out. Maybe the issue is more that $A_n$ has unusually many classes by simple group standards?
Dec
15
reviewed Approve What is interesting/useful about Castelnuovo-Mumford regularity?
Dec
15
awarded  Nice Question
Dec
15
comment Why do sporadic simple groups have so few conjugacy classes?
The fact that the Monster needs nearly 200000 dimensions to be represented linearly over any field is striking in its own right, but only a few of the sporadics are like this.
Dec
14
asked Why do sporadic simple groups have so few conjugacy classes?
Dec
14
awarded  Custodian
Dec
14
reviewed Reject Time estimate to determine if a number is prime
Dec
14
awarded  Custodian