On the rank of Leopoldt’s and Gross’s regulator maps

Abstract

We generalize Waldschmidt’s bound for Leopoldt’s defect and prove a similar bound for Gross’s defect for an arbitrary extension of number fields. As an application, we prove new cases of Gross’s finiteness conjecture (also known as the Gross–Kuz’min conjecture) beyond the classical abelian case, and we show that Gross’s $p$-adic regulator has at least half of the conjectured rank. We also describe and compute non-cyclotomic analogues of Gross’s defect.