Skip to main content
Alex Gavrilov's user avatar
Alex Gavrilov's user avatar
Alex Gavrilov's user avatar
Alex Gavrilov
  • Member for 14 years, 2 months
  • Last seen this week
  • Russia
comment
How can I distinguish a genuine solution of polynomial equations from a numerical near miss?
The problem is, sometimes you can't reformulate the problem this way. If there are 1000 equations with 200 variables and this is it, then interval arithmetic is useless. (As well as anything else, I guess.)
comment
A question about spectral properties of a non-amenable group
H. Kesten. Symmetric random walks on groups. Trans. Amer. Math. Soc. 92, 336-354 (1959).
comment
Tools for constructing homeomorphisms between 4-manifolds
Thank you. Siebenmann's article is quite a nice reading. By the way, one quote from it: "One can expect that mathematicians will consequently come to use freely the notions of homeomorphism and topological manifold untroubled by the frustrating difficulties that worried their early history". It was 50 years ago!
revised
Loading…
revised
Loading…
Loading…
revised
Cone-Torus intersection in 3D
added 2 characters in body
Loading…
answered
Loading…
comment
How to check that whether or not a surface is a K3 surface?
If there were a "normal form" for surfaces in $\mathbb{P}^3$, the life of algebraic geometers specialized in moduli spaces would be a lot easier.
comment
Can we specify the value of harmonic forms at a point?
This may be a difficult part, so if you want to fill the details in, then you better ask an expect. (I am familiar with differential geometry, but this point is about analysis on manifolds, where I am lacking.) Simply put, the Weitzenböck identity is helpful because the Bochner Laplacian is better then the Hodge Laplacian in the following way: if it is zero, then the form is covariant constant and, in particular, does not vanish (which is far from the case for the Hodge one).
Loading…
accepted
Loading…
comment
Are there examples of conjectures supported by heuristic arguments that have been finally disproved?
Edwin Moise in his well known paper "Affine structures ..." (Annals of Math,1952) for this sort of arguments makes a reference to "Zur Topologie der Mannigfaltigkeiten", G Nöbeling, Monatshefte für Mathematik und Physik, 1935. I can't say much more for I could not read it even if I had it (I am not very good at German). On the undergrad level, it is plausible at least for manifolds because continuous maps can be approximated by piecewise linear ones. Of course, today we know that this logic is wrong.
Loading…
comment
Cases where the number field case and the function field (with positive characteristic) are different
Reading Weil's "Basic Number theory" I always feel that this book would have improved if Weil didn't stretch this analogy as far as he did.
revised
Partial product of Euler factors
added 15 characters in body
Loading…
awarded
1
4 5
6
7 8
27