0
votes
0answers
221 views
Gaussian random vectors [closed]
If $(X,Y)$, $(Z,X)$ and $(Y,Z)$ are all Gaussian random vectors, is $(X,Y,Z)$ a Gaussian random vector?
7
votes
1answer
523 views
Quantum equivariant $K$-theory and DAHA.
Theorem 3.2 of the paper "Quantum cohomology of the Springer resolution" by Braverman, Maulik and Okounkov relates equivariant quantum cohomology of the cotangent bundle of $G/B$ …
1
vote
3answers
1k views
Projective closure of affine curve.
Is there a generalized method to find the projective closure of an affine curve? For example, I read that the projective closure of y^2 = x^3−x+1 in P2 is y^2·z = x^3−x·z^2+z^3.
I …
4
votes
3answers
715 views
Why is the Euler characteristic of powers of a line bundle a polynomial in the power?
Mumford's book Abelian Varieties asserts that for a line bundle L on a projective variety (if necessary, you can assume it is as nice as possible), the Euler characteristic $\chi(L …
1
vote
1answer
219 views
Is this measure related to treewidth?
Let p=(v1,…,vn) be a self-avoiding walk in a graph G. Let d(p) be the number of unique i, 1≤i<n such that there's a self-avoiding walk q that starts at vn and ends at vi with …
-1
votes
0answers
171 views
What is the definition of the dimension of a group? [closed]
This concept appears in some classical studies about thin sets. For example, a well-known theorem asserts that if dim G is finite, then every compact independent subset of G is tot …
5
votes
1answer
730 views
Galois groups via cohomology
I would like to know about references for the following result (point 3):
Let $K/k$ be a normal extension (I am interested in number fields, but everything should work in fields …
4
votes
2answers
343 views
Can H-space multiplication always be straightened so that mult.-by-id. is the identity on the nose?
In JP May's Concise Course in Algebraic Topology, on page 143 he says that the left- and right-multiplication-by-identity maps $\lambda:X\rightarrow X$ and $\rho:X\rightarrow X$ sp …
3
votes
2answers
465 views
References and applications involving the Krull Toplogy
I was wondering if anyone can suggest a reference which treats the Krull topology. Most of the books I have found don't go into any kind of detail.
It is my understanding that the …
7
votes
1answer
619 views
Integral expression for zeta(2)
By computing the sum of all Bernoulli numbers via Borel summation (I learned this technique from Varadarajan's excellent book Euler through time. A new look at old themes, 2006) I …
1
vote
0answers
206 views
Topology for test functions [closed]
One naive way to define a topology on test functions ${\mathcal D}(\Omega)$ would be to exhaust $\Omega$ by compacts $(K_n)$ and to take the metric induced by the semi-norm system
…
0
votes
0answers
110 views
Equation for getting the length of the semi-minor axis (of an ellipse) [closed]
I'm looking for an equation that can help me determine the length of the semi-minor axis.
I know the length of the major axis and the Cartesian coordinates of a point somewhere on …
3
votes
1answer
176 views
Image of composite morphisms
I am new to categories and I found in a book that it is possible to construct a category in which the following are true: there exist morphisms $f:A \to B$ and $g:B \to C$, and mon …
0
votes
0answers
162 views
AES key schedule: round 1 and round 0 equal?
is there a key that gives round 1 and round 0 that are equal?
(a0,b0,c0,d0) = (a1,b1,c1,d1)
how many keys like that exist?
can it continue to round 2? round3...?
3
votes
4answers
652 views
Smoothness of Symmetric Powers
Here's something that's been bothering me, and that's come up again for me recently while reading some stuff about Hilbert schemes of points (Nakajima's lectures, specifically):
L …
