Title: Tate-Shafarevich groups over anticyclotomic Z_p extensions at supersingular primes

Abstract Let E be an elliptic curve defined over Q with supersingular reduction at p and K an imaginary quadratic extension of Q. We will analyze the structure of the p-primary part of the Tate-Shafarevich group over K_\infty, the anticyclotomic Z_p extension of K, by viewing it as a module over Z_p[Gal(K_\infty/K)].