On K-stability of Calabi-Yau fibrations
Masafumi Hattori
TL;DR
The paper establishes a precise equivalence between uniform adiabatic K-stability of Calabi–Yau fibrations over curves and log-twisted K-stability of the base pair with discriminant and moduli divisors. It develops a framework linking base stability to total-space stability via delta-invariants and a J-stability criterion extended to singular settings, enabling existence results for cscK metrics on smooth total spaces. A key contribution is showing that delta-invariant convergence translates base K-stability into adiabatic stability of the fibration, with concrete applications to rational elliptic surfaces. The results provide a robust method to detect adiabatic stability from base data and to construct moduli in the K-stable regime, impacting the study of canonical metrics and moduli of polarized fibrations.
Abstract
We show that Calabi-Yau fibrations over curves are uniformly K-stable in an adiabatic sense if and only if the base curves are K-stable in the log-twisted sense. Moreover, we prove that there are cscK metrics for such fibrations when the total spaces are smooth.
