bio | website | cs.ox.ac.uk/people/… |
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location | Oxford, United Kingdom | |
age | 51 | |
visits | member for | 4 years, 2 months |
seen | 53 mins ago | |
stats | profile views | 1,950 |
Jan 28 |
comment |
Induced subgraphs of small strongly regular graphs
in my old papers I reconstructed subgraphs induced on the common neighbours of a pair of non-adjacent vertices. But it was always the case that I knew much more about $N(v)$ than here. |
Jan 26 |
comment |
Irreducibility of a polynomial
oops, sorry, voted to reopen. |
Jan 26 |
comment |
Can all unit-distance graphs have their vertices at algebraic integers?
@Ilya: ah, right. And not only into a 6-wheel, but any subgraph of the hexagonal lattice. I wonder if this is the complete answer. |
Jan 26 |
comment |
Can all unit-distance graphs have their vertices at algebraic integers?
@Ilya: good point. This means that $G$'s with a homomorphisms to 6-cycle is a good class, in terms of the original question. (No idea why such graphs are interesting though) :-) |
Jan 26 |
revised |
Largest eigenvalue adjacency matrix-link deletion
typo fixed |
Jan 26 |
comment |
Can all unit-distance graphs have their vertices at algebraic integers?
How about adding a bit of intuition, say do you know such $f$ for the triangle? (and if yes, then one immediately has $f$ for the 3-colourable graphs). |
Jan 26 |
comment |
When can the group of permutations generated by the translations of a group be identical with the group of all permutations on this group?
en.wikipedia.org/wiki/Cayley%27s_theorem ? |
Jan 26 |
revised |
Can every finite abelian $p$-group with duality pairing be written as cokernel of a symmetric matrix over the $p$-adic integers?
edited title |
Jan 24 |
comment |
Can a graph be reconstructed from its cycle lengths?
It seems that if you know this sequence and the adjacency matrix of the graph, then you can compute the matching polynomial, which is #P-complete. |
Jan 23 |
comment |
Open access journals in number theory
IMHO a publication of a close to final version on arxiv.org is good enough for all practical purposes. |
Jan 23 |
comment |
accelerate convex optimization by proximal projection
can't you just stop your quadratic optimisations early? |
Jan 23 |
comment |
research on the structure/properties of permutation matrix/table with $(i,j)th$ entry as $\pi_j\circ \pi_i^{-1}$
it's not clear what kind of order on permutations you are talking about, and, indeed, what the entries of these tables are. |
Jan 18 |
comment |
When is edge colored circulant isomorphism polynomial?
@joro - sure, they use the definition I mentioned, too. |
Jan 18 |
comment |
When is edge colored circulant isomorphism polynomial?
In your reduction attempt, you lose the needed automorphisms, so it does not work. |
Jan 18 |
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When is edge colored circulant isomorphism polynomial?
Edge-coloured circulant graphs are edge-coloured graphs admitting a cyclic transitive automorphism group. Colouring here is just a map from a set of colours to the edges. |
Jan 18 |
reviewed | Approve Saito-Wright definition of Rickart C*-algebras |
Jan 18 |
comment |
Minimally intersecting subsets of fixed size
to generalise my example to another small $k$, take a the affine space of bigger dimension; in more generality, you can play with putting together different 2-designs with appropriate parameters. |
Jan 18 |
comment |
Minimally intersecting subsets of fixed size
generalising for arbitrary $k$ is hard, as optimal codes are in general not known. |
Jan 16 |
comment |
Minimally intersecting subsets of fixed size
@Bill - I added a possible construction to my answer. |
Jan 16 |
revised |
Minimally intersecting subsets of fixed size
answering a question from the comment |