Published online by Cambridge University Press: 12 May 2016
Let E/Q be an elliptic curve, p a prime and K ∞/K the anticyclotomic Zp -extension of a quadratic imaginary field K satisfying the Heegner hypothesis. In this paper we give a new proof to a theorem of Bertolini which determines the value of the Λ-corank of Selp∞ (E/K ∞) in the case where E has ordinary reduction at p. In the case where E has supersingular reduction at p we make a conjecture about the structure of the module of Heegner points mod p. Assuming this conjecture we give a new proof to a theorem of Ciperiani which determines the value of the Λ-corank of Selp∞ (E/K ∞) in the case where E has supersingular reduction at p.