On the stability of holomorphic families of endomorphisms of ${\mathbb P}^k$
François Berteloot, Xavier Buff
TL;DR
This work analyzes the stability of holomorphic families of degree $d\ge 2$ endomorphisms of $\mathbb{P}^k$ parameterized by a simply connected complex manifold $M$. It introduces and interrelates stability notions through equilibrium webs and laminations, culminating in an equivalence result that unifies $\mu$-stability with weak and partial forms of stability. The approach hinges on the Lyapunov function $L(\lambda)=\int_{\mathbb{P}^k} \ln|{\rm Jac} f_\lambda|\, d\mu_\lambda$, its $dd^c L$-formula, and an approximation formula by repelling cycles, tying stability to critical dynamics and the distribution of repellers. The main theorem shows that, for simply connected $M$, the various stability notions are equivalent, extending prior work and clarifying the behavior of repelling-cycle bifurcations across the family. These results provide a rigorous framework for understanding stability propagation in higher-dimensional holomorphic dynamics.
Abstract
In the context of holomorphic families of ${\mathbb P}^k$ endomorphisms, we show that various notions of stability are equivalent. This allows us to both extend and simplify the architecture of the proof of certain results of [BBD]
