Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
Algebraic and geometric theory of quadratic forms and symmetric bilinear forms, e.g., values attained by quadratic forms, isotropic subspaces, the Witt ring, invariants of quadratic forms, the discriminant and Clifford algebra of a quadratic form, Pfister forms, automorphisms of quadratic forms.
4
votes
Pythagorean number in Artin's theorem on nonnegative rational fractions
Apparently, we have $N \leq 2^n$. See these slides by Jean-Louis Colliot-Thélène, belonging to a lecture he gave in Leiden in 2011:
http://www.math.u-psud.fr/~colliot/Kloostermanlezing.pdf
First, he w …
8
votes
Accepted
Is any quadric birational to a product of Brauer-Severi varieties?
Consider the projective quadric $V$ given by
$$
2x^2+y^2+z^2+w^2=0
$$
over $\mathbb{Q}$. Inspired by Jason Starr's remark on splitting fields, I will prove that $V$ is not birational to a product of S …