Timeline for Homomorphism of Legendre curve
Current License: CC BY-SA 2.5
2 events
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| Apr 11, 2010 at 12:45 | comment | added | Kevin Buzzard | Before computer programs were available to do this sort of thing, this is how Swinnerton-Dyer et al used to compute Selmer groups by hand. One can even isolate the part of (K^x/K^x^2)^2 corresponding to the Selmer group relatively easy, and often prove that Sha has no 2-torsion by explicit hand calculations (as long as one is lucky enough to find enough points to explain Selmer). This is in some sense a dying art now. I learnt it from Cassels and still teach it, well, a variant of it, when there is only one 2-torsion point, to 4th year undergraduates. In practice I use a computer though :-) | |
| Apr 11, 2010 at 8:51 | history | answered | Bjorn Poonen | CC BY-SA 2.5 |