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bio website cs.ox.ac.uk/people/…
location Oxford, United Kingdom
age 51
visits member for 4 years
seen 16 hours ago

Oct
2
comment maximizing a function involving factorial
I'd use the gamma function, which is nice and smooth, and you can use calculus on it. en.wikipedia.org/wiki/Gamma_function
Oct
1
revised Regular graphs with strongly regular edge colorings
added 188 characters in body
Oct
1
revised Regular graphs with strongly regular edge colorings
deleted 178 characters in body
Oct
1
comment Why is the spectrum of this matrix product invariant with respect to order of the multiplicants?
shouldn't $n$'s in the formula for $\sigma$ actually be $k$'s?
Oct
1
revised Regular graphs with strongly regular edge colorings
more info added
Oct
1
revised Regular graphs with strongly regular edge colorings
deleted 12 characters in body
Oct
1
answered Regular graphs with strongly regular edge colorings
Sep
30
awarded  Explainer
Sep
25
comment pencil of quadrics consisting of singular quadrics
it is essentially about pencils of matrices $A_q$, with $q(x)=x^\top A_q x$. Probably you can only find this in solution sheets to some course or textbook...
Sep
25
comment Optimization problem involving an entrywise function
and of course if you do not say anything about $\phi$ then it looks pretty hopeless,
Sep
25
comment Optimization problem involving an entrywise function
note that $X^\top\Sigma X$ need not be invertible.
Sep
24
revised Hilbert's Theorem on $L_2$ norm of polynomials in $\mathbb{Z}[X]$ - Explicit construction and a converse?
typo in the year
Sep
24
comment Conjectured integral for Catalan's constant
can you rewrite your last integral in terms of functions of a real variable?
Sep
23
comment nonnegativity conditions for a polynomial in two variables
for more variables nothing of this sort is known; Hilbert's (1893) paper substantially uses quite tricky algebraic geometry of complex plane curves (something that nowadays one would explain using en.wikipedia.org/wiki/Theta_characteristic)
Sep
23
comment nonnegativity conditions for a polynomial in two variables
for bivariate polynomials the much better route is outlined in my answer.
Sep
22
revised nonnegativity conditions for a polynomial in two variables
more references, and an explanation
Sep
22
answered nonnegativity conditions for a polynomial in two variables
Sep
22
comment Complexity of Untwisting Polygons
generating random polygons is a different story then; they care about the uniformity, etc...
Sep
22
comment Complexity of Untwisting Polygons
I'm not sure it's not better to forget all the edges and just construct a polygon directly.
Sep
22
awarded  Custodian