Zero-cycles on a product of elliptic curves over a $p$-adic field

Abstract

We consider a product $X=E_1\times \cdots \times E_d$ of elliptic curves over a finite extension $K$ of ${\mathbb{Q}}_p$ with a combination of good or split multiplicative reduction. We assume that at most one of the elliptic curves has supersingular reduction. Under these assumptions, we prove that the Albanese kernel of $X$ is the direct sum of a finite group and a divisible group, extending work of Raskind and Spiess to cases that include supersingular phenomena. Our method involves studying the kernel of the cycle map $C{H}_0(X)/p^n\to H_{\text{eˊt}}^{2d}(X,{\mu }_{p^n}^{\otimes d})$. We give specific criteria that guarantee this map is injective for every $n\ge 1$. When all curves have good ordinary reduction, we show that it suffices to extend to a specific finite extension $L$ of $K$ for these criteria to be satisfied. This extends previous work of Yamazaki and Hiranouchi.

28 pages