17/09/2004, 11:30 — 12:30 — Room P3.10, Mathematics Building
Ciro Ciliberto, Università di Roma II
Degeneration techniques in algebraic geometry
In the last 2 lectures I will:
- introduce (higher) secant varieties, (weakly) defective varieties and recall Terracini’s lemma;
- I will talk about the famous theorem of Severi which classifies 1- defective surfaces;
- I will talk about terracini’s extension to higher secant surfaces;
- I will prove a bound on the degree of secant varieties;
- I will classify surfaces for which the bound is achieved, showing how all this is related to castelnuovo–enriques’ theorem above.
Parts 4 & 5 above is recent joint work with F. Russo.
