3,554 reputation
1432
bio website stanford.edu/~rrwill
location California
age
visits member for 5 years, 8 months
seen yesterday
Interested in algorithms, complexity, and anything that the rest of mathematics can say about these two.

Jun
5
comment does the “convolution theorem” apply to weaker algebraic structures?
Those comments address the case of commutative rings. The above structures (in my answer) are not commutative rings.
Jan
28
awarded  Taxonomist
Jan
9
revised does the “convolution theorem” apply to weaker algebraic structures?
updated, includes new research
Dec
16
awarded  Yearling
Dec
6
awarded  Notable Question
Nov
2
awarded  Enlightened
Nov
2
awarded  Nice Answer
Feb
18
awarded  Nice Answer
Dec
16
awarded  Yearling
Dec
10
awarded  Nice Answer
Nov
22
awarded  Enlightened
Nov
22
awarded  Nice Answer
Nov
5
comment Finding a cycle of fixed length
Not sure what you're asking. There can be $\Omega(n^4)$ cycles of length 4 in a graph, so $O(n^4)$ time is the best you can hope for asymptotically if you want to list all 4-cycles. If you're asking how to get the above algorithm to produce a 4-cycle in $O(n^2)$ time when one exists, that's also pretty obvious...
Oct
11
awarded  Caucus
Oct
11
awarded  Constituent
Sep
10
awarded  Nice Answer
Jun
25
awarded  computational-complexity
Jun
3
awarded  Good Answer
Dec
16
awarded  Yearling
Jun
26
awarded  Nice Answer