41,822 reputation
653137
bio website math.temple.edu/~rivin
location USA
age
visits member for 4 years, 4 months
seen 5 hours ago

Professor of Mathematics at Temple University. Regius Professor of Mathematics at St Andrews starting Fall 2015.


1d
comment finite cyclic group have subgroup of prime index
Yes, it is true, but you should prove it yourself.
2d
comment Proof for additivity of cumulants
@seno44 I see no reason why the binomial theorem would not give you what you want by induction.
2d
answered Analytical value for the first eigenvalue of a certain spherical triangle
Mar
24
comment Real Zeros - tail estimate
@oferzeitouni Do you have a reference for the gaussian tail? After posting the question, I found that Hough-Krishnapur-Peres-Virag talk about it, but I think they only get an exponential decay (in some regime). Thanks!
Mar
23
answered How compute combinatorial expression
Mar
23
asked Real Zeros - tail estimate
Mar
23
revised Obtain any 3-manifold from repeating surgeries on knots in $S^3$
grammatical error
Mar
23
answered algorithm of polytope
Mar
23
comment Obtain any 3-manifold from repeating surgeries on knots in $S^3$
A relative of yours?
Mar
23
answered Obtain any 3-manifold from repeating surgeries on knots in $S^3$
Mar
23
comment A hypergeometric identity
(a) What does "a simple proof" mean? (b) Do you know of a complicated proof?
Mar
22
comment Obtain any 3-manifold from repeating surgeries on knots in $S^3$
Do you know of an easier proof without f.g.?
Mar
22
comment When are the adjacency matrices of non-isomorphic graphs similar?
Yes, I am just saying that the algorithm of checking for similarity first will (in practice) greatly underperform standard heuristic. I certainly agree that the question is of theoretical interest (though is probably very hard).
Mar
22
comment Obtain any 3-manifold from repeating surgeries on knots in $S^3$
By the way, I have never looked at Dehn's proof. I wonder if the proof is easier if you don't care about finite generation (which you don't, for this question).
Mar
22
comment When are the adjacency matrices of non-isomorphic graphs similar?
It should be noted that most graph isomorphism testing heuristics are mp MUCH faster than cubic, usually, so this question is not of great practical significance...
Mar
22
comment Obtain any 3-manifold from repeating surgeries on knots in $S^3$
But my understanding has always been that Dehn's theorem was the nontrivial part.
Mar
22
comment Obtain any 3-manifold from repeating surgeries on knots in $S^3$
Why do you attribute this theorem to Lickorish, instead of Dehn?
Mar
21
answered Find matrices which generate a given set of vectors
Mar
20
comment Find matrices which generate a given set of vectors
What does "small" mean?
Mar
20
comment Continuous maps which send intervals of $\mathbb{R}$ to convex subsets of $\mathbb{R}^2$
Ah, did not notice the 1-1 hypothesis...