On the p-adic Stark conjecture at s=1 and applications
arXiv:1703.06803 · doi:10.1112/jlms.12310
Abstract
Let E/F be a finite Galois extension of totally real number fields and let p be a prime. The `p-adic Stark conjecture at s=1' relates the leading terms at s=1 of p-adic Artin L-functions to those of the complex Artin L-functions attached to E/F. We prove this conjecture unconditionally when E/Q is abelian. We also show that for certain non-abelian extensions E/F the p-adic Stark conjecture at s=1 is implied by Leopoldt's conjecture for E at p. Moreover, we prove that for a fixed prime p, the p-adic Stark conjecture at s=1 for E/F implies Stark's conjecture at s=1 for E/F. This leads to a `prime-by-prime' descent theorem for the `equivariant Tamagawa number conjecture' (ETNC) for Tate motives at s=1. As an application of these results, we provide strong new evidence for special cases of the ETNC for Tate motives and the closely related `leading term conjectures' at s=0 and s=1.
35 pages; v5 accepted version to appear in Journal of the London Mathematical Society; v4 minor revisions and appendix by Tommy Hofmann, Henri Johnston and Andreas Nickel added; v3 minor revisions; v2 minor revisions; comments welcome