A flower theorem in $\mathbb{C}^n$
Kémo Morvan
TL;DR
This work extends the Leau-Fatou flower picture to holomorphic germs $f:(\\mathbb{C}^n,0)\\to(\\mathbb{C}^n,0)$ tangent to the identity that fix coordinate hyperplanes. By normalizing to $\\langle a,M\\rangle = -1$ and exploiting the one-dimensional reduction along $\\mathbf{x}^m$, the authors construct $d = \\gcd(M)$ forward and backward parabolic domains on which forward or backward orbits converge to $0$, and provide explicit Fatou coordinates that conjugate $f$ (or $f^{-1}$) to a translation in suitable coordinates. The central result is a higher-dimensional flower theorem: these domains, together with the fixed set $\\{\\mathbf{x}^M=0\\}$, form a neighborhood of the origin and yield a full foliation by parabolic petals with holomorphic conjugacies to translations; a complementary divergence result shows nonexistence of such petals when a certain real-part condition fails. Overall, the paper generalizes the classical one-dimensional dynamics to several complex variables, employing invariant functions, approximate Fatou coordinates, and patching techniques to obtain exact Fatou coordinates on invariant domains.
Abstract
We prove an analog of the flower theorem for non-degenerate reduced tangent to the identity germs that fix the coordinate hyperspaces in any dimension.
