Upper-bound for the number of robust parabolic curves for a class of maps tangent to identity

Innocenti, Francesco Degli; Frosini, Chiara

Upper-bound for the number of robust parabolic curves for a class of maps tangent to identity

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Description

The Leau-Fatou flower theorem completely describes the dynamic behavior of $1-$dimensional maps tangent to the identity. In dimension two Hakim and Abate proved that if $f$ is a holomorphic map tangent to the identity in $\mathbb{C}^2$ and $ν(f)$ is the degree of the first non vanishing jet of $f-Id$ then there exist $ν(f)-1$ robust parabolic curves (RP curves for short), namely attractive petals at the origin which survive under by blow-up. The set of the exponential of holomorphic vector fields (of order greater than or equal to two), $Φ_{\geq 2}(\mathbb{C}^2,0)$, is dense in the space of germs of maps tangent to the identity. In this paper we give an upper-bound for the number of robust parabolic curves of $f\in Φ_{\geq 2}(\mathbb{C}^2,0) .$