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bio website math.temple.edu/~rivin
location USA
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visits member for 4 years, 7 months
seen 6 hours ago

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


20h
comment Stability of the Solar System
First, they came for Mars...
20h
comment Stability of the Solar System
@GerhardPaseman Planets leaving, other planets crashing into the Sun. O, the humanity!
21h
answered Probability a random matrix contains a short integer vector in its kernel
21h
answered Stability of the Solar System
23h
comment How to prove the existence of the polytope in $\mathbb{R}^d$ with a given number of faces, minimizing the isoperimetric ratio?
@student The volume is the same as when you would count the face one, but the area is bigger.
23h
answered How to prove the existence of the polytope in $\mathbb{R}^d$ with a given number of faces, minimizing the isoperimetric ratio?
1d
comment Algebraic independence in normed spaces
By the way, I had trouble backing out the statement from the lemma you mention (I did not try very hard to unravel all the jargon, it's true...)
1d
comment Identities involving sums of Catalan numbers
Your RHS equals the expression in the answer...
2d
answered Identities involving sums of Catalan numbers
2d
comment Algebraic independence in normed spaces
I don't see how you would be able to say anything in general (since the algebricity of the $l^2$ norm is obviously essential); the $l^p$ case is obviously quite special.
2d
answered Is the boundary of an open, regular, bounded, path-connected, and simply connected set a Jordan curve
2d
revised Determining if a matrix is orthogonal
added more info.
2d
comment Determining if a matrix is orthogonal
@YCor Yes, correct. That's what happens when you do this too late at night :)
2d
answered Determining if a matrix is orthogonal
2d
revised Determining if a matrix is orthogonal
fixed TeX
Jul
1
comment How to determine an unitary operator involved in an unitary transformation?
Why? What's wrong with the 1962 method?
Jul
1
answered How to determine an unitary operator involved in an unitary transformation?
Jul
1
answered Given $x$ in a path-connected open set $S$ on the plane, are there non-crossing paths from $x$ to every point in $\partial S$?
Jul
1
answered $P_3$-factors for 3-regular, 3-connected cubic graphs
Jul
1
comment $P_3$-factors for 3-regular, 3-connected cubic graphs
Sleuthing shows that $P_k$ is a path on $k$ vertices, so the OP's question is whether the vertices of $G$ can be decomposed into triples, where each triples forms the vertex set of a path on three vertices, and these paths are disjoint.