An analogue of Hilbert's 10th problem for fields of meromorphic functions over non-Archimedean valued fields

Abstract

Let K be a complete and algebraically closed valued field of characteristic 0. We prove that the set of rational integers is positive existentially definable in the field M of meromorphic functions on K in the language L z ∗ of rings augmented by a constant symbol for the independent variable z and by a symbol for the unary relation “the function x takes the value 0 at 0”. Consequently, we prove that the positive existential theory of M in the language L z ∗ is undecidable. In order to obtain these results, we obtain a complete characterization of all analytic projective maps (over K) from an elliptic curve E minus a point to E , for any elliptic curve defined over the field of constants.