Coleman-Gross Heights and $p$-adic N\'eron Functions on Jacobians of Genus $2$ Curves

Abstract

We develop a theory of $p$-adic N\'eron functions on abelian varieties, depending on various auxiliary choices, and show that the global $p$-adic height functions constructed by Mazur and Tate can be decomposed into a sum of $p$-adic N\'eron functions if the same auxiliary choices are made. We also consider a decomposition of the $p$-adic height constructed by Coleman and Gross for good reduction, and extended to arbitrary reduction by Colmez and Besser, into a sum of certain local height functions for Jacobians of odd degree genus~$2$ curves. We show that this local height function is equal to the $p$-adic N\'eron function with the same auxiliary choices, regardless of the reduction type of the curve. This extends work of Balakrishnan and Besser for elliptic curves. When the curve has semistable reduction and the reduction of the Jacobian is ordinary, we also describe the $p$-adic N\'eron function that arises from the canonical Mazur--Tate splitting explicitly in terms of a generalisation of the $p$-adic sigma function constructed by Blakestad.