bio | website | front.math.ucdavis.edu/… |
---|---|---|
location | Cornell | |
age | 45 | |
visits | member for | 5 years, 10 months |
seen | 4 hours ago | |
stats | profile views | 11,434 |
Math professor at Cornell,
PhD 1996
Sep
1 |
comment |
Where to buy premium white chalk in the U.S., like they have at RIMS?
Please don't pollute this page; my email address is trivial to find (e.g. click on my name). |
Aug
31 |
comment |
Reference for the statement that the complement of an affine open has codimension one
I'd've called this "algebraic Hartogs' theorem". If $Y$ is codimension 2 in $X$, then functions on $U$ should extend across $Y$, i.e. $U$ shouldn't be affine. |
Aug
5 |
awarded | Nice Answer |
Jul
24 |
awarded | Popular Question |
Jul
20 |
awarded | Nice Answer |
Jul
18 |
awarded | Nice Answer |
Jul
9 |
revised |
Is there a tropical geometric proof for counting genus g curves in any n dimensional projective space?
Fixed Soibelman |
Jul
6 |
comment |
Orientation form on the blow up of a Kaehler manifold
I agree that in that example you could pick the form you said. What my example shows is that if you pick a random form and then scale it to be good for $X$, it may not work for $Y$. So if you want it for both (which I'm not convinced you really do -- but it's what you wrote), you need a real argument. |
Jul
4 |
comment |
Orientation form on the blow up of a Kaehler manifold
I don't see how you can normalize the integral to be 1 on $X$ and $Y$ simultaneously. For example, take $X$ to be the product of two $\mathbb P^1$s with areas $r, 1/r$, and $Y = \mathbb P^1 \times pt$. |
Jun
30 |
comment |
Smooth morphism to homogeneous spaces and fibers
I usually use "$f$ is equivariant". |
Jun
30 |
comment |
Picard group of a quotient of a group by its maximal parabolic subgroup
You can't say "the" maximal parabolic; there's usually more than one, even up to conjugacy. But for every such $P$ this is true. |
Jun
30 |
answered | Shared maximum eigenvector |
Jun
28 |
revised |
What is deforming this non-complete intersection like?
made title more specific to the question |
Jun
28 |
reviewed | Approve What is deforming this non-complete intersection like? |
Jun
26 |
awarded | Nice Question |
Jun
26 |
comment |
Number of $\mathbb F_p$ points constant mod $p$?
Your #4 sounds like "what does it imply?" rather than "what does it suggest?" (what would imply it, that one should be on the lookout for?). I have a certain class of varieties; I don't know what properties they have, but now I'm going to try to prove rational connectivity directly for them (not actually imply it from the point-counting fact). |
Jun
26 |
comment |
Number of $\mathbb F_p$ points constant mod $p$?
I'd certainly like to compute $\#X(\bf F_p)$ but don't expect to have much luck. |
Jun
25 |
asked | Number of $\mathbb F_p$ points constant mod $p$? |
Jun
21 |
comment |
A homeomorphism between total spaces with same fiber and base spaces not homotopic
Or more generally, if $F\to E\to B$ is a bundle with $E$ not a product, then $F\times E \to E$, $F\times E \to F\times B$ works. |
Jun
18 |
comment |
Combinatorial results by Poincaré duality
If you're willing to extend this from "Poincar\'e duality" to "properties of Betti numbers", then you could include Hard Lefschetz in your toolset, and get Stanley's proof of the Upper Bound Theorem for the number of faces of a simplicial polytope. |