5,389 reputation
930
bio website cs.ox.ac.uk/people/…
location Oxford, United Kingdom
age 51
visits member for 4 years, 9 months
seen 2 days ago

May
9
reviewed Leave Open Where to buy premium white chalk in the U.S., like they have at RIMS?
May
9
reviewed Close What are the applications of Voronoi diagrams in pure mathematics?
May
8
comment What is the complexity of intersecting two matrix algebras over a finite field?
The only hope seems to be to compute (partial) decompositions (using Meataxe, see e.g. homepages.warwick.ac.uk/~mareg/download/papers/bham_95/…) of the representations of the groups generated by $\mathcal{A}$ and $\mathcal{B}$, and hope they have small factors only. Then linear algebra becomes faster.
May
7
comment What is the complexity of intersecting two matrix algebras over a finite field?
Computational representation theory of groups is harder than linear algebra (this is a metatheorem :-)). My bet is that in general there cannot be a speedup hoped for in the question.
May
7
reviewed Close Representation Theory of Lie Groups: Reference Request
May
7
reviewed Close Backlund counting formula for Dirichlet L-functions?
May
7
reviewed Close cup-length of the first Chern class of complex grassmannian
May
5
reviewed Close If the quotient of an algebraic space $X$ by a finite group is a scheme, is $X$ a scheme?
May
5
comment If the quotient of an algebraic space $X$ by a finite group is a scheme, is $X$ a scheme?
I'm voting to close this question as off-topic because it has been answered in the comments
May
4
reviewed Close Examples of $C^*$-algebras in Noncommutative Geometry from A. Connes
May
2
comment A table for irreducible integral representation of finite cyclic groups
table? A theorem, perhaps...
May
2
reviewed Close Dimension of Ext modules
May
2
reviewed Close Heat asymptotics
May
1
comment Do unit quaternions at vertices of a regular 4-simplex, one being 1, generate a free group?
wouldn't this imply that the multiplicative group of quaternions contains a free group on 4 symbols? This is rather surprising to me.
Apr
30
revised Number of matrices with given Smith normal form
tags added
Apr
30
answered Number of matrices with given Smith normal form
Apr
30
reviewed Close Two basic questions concerning geometrically ruled surfaces.
Apr
30
comment the complex representations of $B(2, \overline{\mathbb{F}_p})$
and what is $B(2,F)$ ? And what is the Mackey method you mention - provide a reference...
Apr
30
revised the complex representations of $B(2, \overline{\mathbb{F}_p})$
texify and improve style
Apr
30
comment Number of matrices with given Smith normal form
this is essentially about counting presentations of a f.g. Abelian group with a given upper bound on size.