Let
be an elliptic curve over
with supersingular reduction at
and let
be a false Tate extension of
. On the one hand, I will explain how to define plus and minus Selmer groups of
over
using ideas from
-adic Hodge theory, generalising works of Kobayashi. On the other hand, I will talk about some congruences of
-values of
which might give rise to a possible definition of plus and minus
-adic
-functions for
, generalising works of Pollack.