Resumen de Model theory of the Frobenius on the Witt vectors
Luc Bélair, Angus Macintyre 
, Thomas Scanlon
We give axiomatizations and prove quantifier elimination theorems for first-order theories of unramified valued fields with an automorphism having a close interaction with the valuation. We achieve an analogue of the classical Ostrowski theory of pseudoconvergence. In the outstanding case of Witt vectors with their Frobenius map, we use the ?-ring formalism from Joyal.
