BSD Plan for 2007-04-16 1. This week: * Galois Cohomology * Sha * Leading coefficient Next week -- p-adic analogues 2. Galois cohomology: Definition of H^n(G,A) for G a group and A an abelian group with a G-action. * cocycles / coboundaries * also can construct via homological algebra as Ext^n_{Z[G]}(Z,A) <--- get right! 3. The long exact sequence. 4. The inf-res sequence. 5. Examples: * kummer theory of fields * quadratic extensions of finite fields * descent on elliptic curves ------------------------------------------ 1. Talk about projects: a. Robert B -- 2-descent b. Dustin M -- ap lists c. Robert M -- congruence graph d. Koopa K -- what we just did; finiteness of Sha's New projects: a. Study computing L_p(E,T) mod p. b. Heegner points package in SAGE (they are coming up)