Asai-Flach classes, p-adic L-functions and the Bloch-Kato conjecture for GO(4)
Giada Grossi, David Loeffler, Sarah Livia Zerbes
TL;DR
This work proves the Bloch–Kato conjecture for critical values of Asai L-functions attached to p-ordinary Hilbert modular forms over real quadratic fields (with p split) and establishes one inclusion in the cyclotomic Iwasawa Main Conjecture for these L-functions. Central to the approach is the Asai–Flach Euler system, the construction of a three-variable p-adic Asai L-function via higher Hida theory, and a regulator formula linking Bloch–Kato logarithms to p-adic L-values; these are interpolated in Hida families through a p-adic Eichler–Shimura comparison with meromorphic interpolation. The paper develops a robust framework of coherent and fp-cohomology, plus Poznań spectral sequences, to express regulator pairings explicitly in terms of p-adic L-values and to prove an explicit reciprocity law in families. The results yield leading-term arguments that connect Euler-system data with L-values, enabling proofs of the Bloch–Kato conjecture in the Asai setting, and establishing an Iwasawa-theoretic inclusion that advances our understanding of the arithmetic of GO(4)–type motives. Overall, the work provides a comprehensive, family-wide bridge between Euler systems, p-adic L-functions, and Selmer groups for Asai representations arising from Hilbert modular forms.
Abstract
We prove the Bloch-Kato conjecture for critical values of Asai L-functions of p-ordinary Hilbert modular forms over quadratic fields (with p split); and one inclusion in the Iwasawa main conjecture for these L-functions (up to a power of p). Along the way, we also prove a version of the p-adic Eichler-Shimura comparison isomorphism for Hida families of Hilbert modular forms.
