590 reputation
412
bio website jolivet.org/timo
location
age 29
visits member for 5 years, 10 months
seen Jul 16 at 12:57

Aug
19
awarded  Popular Question
Jun
22
answered Brun's algorithm
Feb
17
comment Spectrum of primitive nonnegative integer matrices
Right now the best I can do is to enumerate all the matrices (using the trace constraint) and test them one by one... Can anyone think of a less stupid approach?
Feb
17
comment Spectrum of primitive nonnegative integer matrices
Gerry, I haven't looked at it for hours but it doesn't seem to be obvious even for $2\times2$ matrices.
Feb
17
comment Spectrum of primitive nonnegative integer matrices
David, unfortunately I would like to avoid the additional zero eigenvalues. Is this question open even without the primitivity assumption? Thanks for the very interesting articles!
Feb
16
asked Spectrum of primitive nonnegative integer matrices
Feb
17
comment What are the most attractive Turing undecidable problems in mathematics?
Note the recent preprint arxiv.org/abs/1312.6700 which improves these results. Undecidability now holds for five 3*3 matrices or two 15*15 matrices.
Jun
14
awarded  Nice Answer
May
27
awarded  Notable Question
Oct
20
awarded  Yearling
Jul
9
awarded  Good Answer
Apr
29
answered Equivalent subshifts
Apr
18
revised What's the difference between 2 and 3?
added 332 characters in body
Apr
18
answered What's the difference between 2 and 3?
Mar
22
comment Importance of Poincaré recurrence theorem? Any example?
The ergodic theorems can be seen as improvements of the Poincaré recurrence theorem, because they relate the time average with the space average. However, the Poincaré theorem is treated first because it is not hard to prove and it is very nice.
Mar
3
answered Computational software in Algebraic Topology?
Dec
5
answered More open problems
Oct
20
awarded  Yearling
Sep
21
comment Lecture notes by Thurston on tiling
I got the above PDF version from Shigeki Akiyama and I am very glad that putting it on my website is useful to some people. It would be great if more people did this because trying to find a paper that is neither on the internet or in libraries can be extremely frustrating!
Aug
20
awarded  Popular Question