8,348 reputation
21745
bio website quoll.uwaterloo.ca
location waterloo
age 66
visits member for 5 years, 5 months
seen 22 hours ago
Professor at University of Waterloo in C&O

1d
reviewed Close Two easy questions of propositional logic
1d
reviewed Close The Gherkin - equation for the curve inoder to calculate the surface area of revolution
Apr
16
reviewed Approve Non Satisfiability of disjuction
Apr
16
reviewed Leave Open Notation for the all-ones vector
Apr
13
reviewed Close Does the diffeomorphism group of an open manifold act naturally on the compactification of the manifold?
Apr
12
reviewed Close Strictly positive element in a C*-algebra
Apr
11
reviewed Close Integral closure of an ideal
Apr
11
reviewed Close Real analytic functions
Apr
11
reviewed Leave Open Spectral decomposition of the shift operator on $\ell_p(N)$
Apr
11
awarded  graph-theory
Apr
10
comment Request for examples of 4-regular, non-planar, girth at least 5 graphs
@gordonRoyle: I was thinking there might be examples on fewer than 19 vertices?
Apr
10
answered Request for examples of 4-regular, non-planar, girth at least 5 graphs
Apr
7
comment About the second largest adjacency eigenvalue of Abelian Cayley graphs
The matrix is $d\times m$ (say). There are $2^d$ binary vectors and they form a group of order $2^d$. The graphs we get is a Cayley graph for this group, with valency $m$. The problem is to compute the eigenvalues in time polynomial in $n$.
Apr
7
comment About the second largest adjacency eigenvalue of Abelian Cayley graphs
The vertices are binary vectors. Two vertices are adjacent if their difference is a column of the given matirx.
Apr
5
reviewed Close How can I prove the hypersurface $M$ is neither convex nor concave?
Apr
1
reviewed Close If $(X_n+Y_n)$ has bounded variance, is the same true for $(X_n)$ and $(Y_n)$?
Apr
1
reviewed Leave Open Dissolution of Tensors
Mar
26
reviewed Leave Open Lovasz's Path removal conjecture
Mar
24
revised About the upper bound on the roots of the matching polynomial
removed ambiguity, fixed typo
Mar
24
comment About the upper bound on the roots of the matching polynomial
@user6818: I have edited my answer. I wrote "gives", which is ambiguous, now it's "divides".