Explicit Motivic Mixed Elliptic Chabauty-Kim

Abstract

The main point of the paper is to take the explicit motivic Chabauty-Kim method developed in papers of Dan-Cohen-Wewers and Dan-Cohen and the author and make it work for non-rational curves. In particular, we calculate the abstract form of an element of the Chabauty-Kim ideal for Z[1/ℓ]-points on a punctured elliptic curve, and lay some groundwork for certain kinds of higher genus curves. For this purpose, we develop an "explicit Tannakian Chabauty-Kim method" using Q ℓ -Tannakian categories of Galois representations in place of Q-linear motives. In future work, we intend to use this method to explicitly apply the Chabauty-Kim method to a curve of positive genus in a situation where Quadratic Chabauty does not apply.