Timeline for Genus of non-reduced curves
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 22, 2019 at 21:19 | answer | added | roy smith | timeline score: 1 | |
| Apr 22, 2019 at 19:49 | comment | added | roy smith | Introduction to Algebraic Geometry, by J.G. Semple and L. Roth, Clarendon Press, Oxford, 1949, reprinted 1986, chapter IV, section 8.2, Intersection of two surfaces in two curves, pages 90-91. I found the old fashioned derivation mysterious, but was able to derive it myself from the adjunction formula, as I noted in my cryptic parenthetical comment above, which I found in my own notes and copied for what it is worth. Unfortunately I did not seem to save the derivation. | |
| Apr 22, 2019 at 13:43 | comment | added | Giulio | @RoySmith could you give me the precise reference please | |
| Apr 21, 2019 at 0:56 | comment | added | roy smith | Maybe this formula from Semple and Roth may help. Genus formula for two surfaces of degrees d,e in projective 3 space meeting in two curves C,C’, of degrees n,n’, and genera p,p’. (Use adjunction formulas for both curves on one surface.) 2(p-p’) = (n-n’)(d+e-4). | |
| Apr 19, 2019 at 10:27 | history | asked | Giulio | CC BY-SA 4.0 |