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bio website cs.ox.ac.uk/people/…
location Oxford, United Kingdom
age 51
visits member for 4 years, 1 month
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7h
comment Which universities teach true infinitesimal calculus?
perhaps "rigorous" or "axiomatic" would be better word than "true".
2d
comment symmetrizability of generalised cartan matrix
either wikipedia is wrong, or this is by definition: en.wikipedia.org/wiki/Cartan_matrix en.wikipedia.org/wiki/Symmetric_matrix#Symmetrizable_matrix
Dec
21
comment Connected components $0-1$ matrices
By definition, the diagonal matrix $I$ is connected.
Dec
21
comment Connected components $0-1$ matrices
Conjugation is certainly much harder to deal with.
Dec
21
comment Connected components $0-1$ matrices
do you require simultaneous permutations of rows and columns (i.e. conjugation by a permutation matrix)? Or you allow different permutations to permute rows and columns?
Dec
19
comment Balanced binary code that “resists” local decoding?
the supports of the codewords either have empty intersection, or intersection of size $2^{k-2}$. So the Hamming distance between any two is $2^{k-1}$ or $2^k$. Thus the minimal distance is $2^{k-1}$.
Dec
18
comment Balanced binary code that “resists” local decoding?
Indeed, thanks for catching this.
Dec
18
comment Balanced binary code that “resists” local decoding?
there is a discrepancy in the definition of $k$ vs examples; e.g. your 1st example corresponds to $k=1$, according to your definition.
Dec
17
comment finding dominating cycles in $2K_2$-free graphs
sure, that is right.
Dec
17
comment automorphism of prime order for group of Lie type in
You can have a look at the "Atlas of finite groups" by J.Conway et al., which has a lot of info on $O_8^+(\mathbb{F}_3)$.
Dec
14
comment when can I say that $UV^T$ is a permutation matrix?
"make an index"? what's that?
Dec
14
comment finding permutation matrix I which minimizes TRACE( I* C*( I^T)* D) matrix
you might like to check out arxiv.org/abs/1403.7721 for up to date references etc
Dec
14
comment finding permutation matrix I which minimizes TRACE( I* C*( I^T)* D) matrix
i.e. instead of n! permutations you might still need to check something like $2^n$ of them.
Dec
14
comment finding permutation matrix I which minimizes TRACE( I* C*( I^T)* D) matrix
well, there was a lot of research done on this problem. it would not be necessary to check a fraction of all permutations of n symbols, but still nobody knows how to check less than exponentially (in terms of n) many of them.
Dec
12
comment Dihedral subgroups of $\mathrm{PSL}_2(\mathbb{F}_q)$
IMHO this is already in L.Dickson's book "Linear Groups", which was reprinted by Dover in 1958.
Nov
15
comment Can any bounded area defined by polynomial inequality in $\mathbb{R}^n$ be partitioned into simply connected finite area such that
it is well-known that any semialgebraic set can be triangulated. The question you ask seems like a particular case of this fact.
Oct
24
comment A number array related to colored necklaces and the primes
A059966 features a reference to a paper by me, and in fact I am well-aware of this relation. :-)
Oct
23
comment A number array related to colored necklaces and the primes
although I don't see an immediate connection.
Oct
23
comment A number array related to colored necklaces and the primes
oeis.org/A001037 is another related sequence, although a
Oct
16
comment Is there an English translation of Minding's 1839 paper?
Assuming it's no coincidence that you have a Dutch name, you certainly can read German without needing to look in a dictionary too much; just try;-) The harder part will be to convert the text to modern terminology, but this equally applies to other languages.