BSD Plan for 2007-04-09 1. Define L_p(E,T) for p odd good ordinary prime. Let alpha be the root of x^2-a_px+p with |alpha| = 1. (0) Recall definition: [r] = 2*pi*i/Omega_E * (...) (a) define a measure on Z_p^*: mu_E(a+p^n*Z_p) = 1/alpha^n*( [a/p^n] - [p*a/p^n]/alpha ) (b) p-adic L-series is a function on characters Hom(Z_p^*, C_p^*) given by sending chi to L_p(E,chi) = integral chi * dmu, whatever that means (it's defined via Riemann sums). (c) Fix the topological generator gamma=1+p of 1+pZ_p, so a character in Hom(1 + p*Z_p, C_p^*) is given by choosing any u in D = { u in C_p : |u-1|_p < 1 } and sending gamma=1+p to it. Let psi_u be that character. For x in Z_p^*, let = x / teich(x mod p). For any u in D, define character chi_u on Z_p^* by chi_u(x) = psi_u() Define a map f: D --> C_p by u |---> L_p(E,chi_u). FACT: f is a p-adic analytic function. Let L_p(E, T) in Q_p(alpha)[[T]] be the Taylor expansion about u=1; this converges { z in C_p : |z|_p < 1 }. We have for u in D that L_p(E, u-1) = L_p(E, chi_u). (d) Riemann sums approximation: The n-th approximation to L_p is P_n(T) = sum(j=0,p^(n-1)-1, sum(a=1,p-1, mu(teich(a)*gamma^j + p^n*Z_p))*(1+T)^j) in Q_p(alpha)[T] and lim_{n-->oo} P_n(T) = L_p(E,T). (e) Interpolation property: (f) Suppose zeta_j is a primitive p^j-th root of unity. Then P_n(zeta_j - 1) is the same for all n > j. Thus P_{n+1} - P_n vanishes at zeta_j - 1 for j < n, so P_{n+1} - P_n is divisible by omega_n(T) = (1+T)^{p^n} - 1. 2. Student feedback: 1. What was clear? 2. What was murky? 3. What should I change to get a perfect evaluation from you?