Timeline for integer solutions to quadratic forms
Current License: CC BY-SA 2.5
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 30, 2010 at 3:01 | vote | accept | john mangual | ||
| Jul 29, 2010 at 23:43 | comment | added | Pete L. Clark | The one thing which is somewhat special about the quadratic form $x^2 + y^2 - z^2 - w^2$ is that its discriminant is a square in the ground field, so the quadric surface is isomorphic to $\mathbb{P^1} \times \mathbb{P}^1$. Otherwise it would -- assuming it has a rational point -- merely be birational to $\mathbb{P}^1 \times \mathbb{P}^1$. | |
| Jul 29, 2010 at 22:46 | comment | added | Qiaochu Yuan | Right. As for finding the first non-trivial zero, that is what the Hasse principle is for. | |
| Jul 29, 2010 at 22:33 | history | answered | Tony Scholl | CC BY-SA 2.5 |