TY - UNPB

T1 - On iterates of rational functions with maximal number of critical values

AU - Pakovich, Fedor

PY - 2021/7/13

Y1 - 2021/7/13

N2 - Let $F$ be a rational function of one complex variable of degree $m\geq 2$. The function $F$ is called simple if for each $z\in \mathbb C\mathbb P^1$ the preimage $P^{-1}\{z\}$ contains at least $m-1$ points. We show that if $F$ is a simple rational function of degree $m\geq 4$ and $F^{\circ l} =G_r\circ G_{r-1}\circ \dots \circ G_1$, $l\geq 1$, is a decomposition of an iterate of $F$ into a composition of indecomposable rational functions, then $r=l$, and there exist M\"obius transformations $\mu_i,$ $1\leq i \leq r-1,$ such that $G_r=F\circ \mu_{r-1},$ $G_i=\mu_{i}^{-1}\circ F \circ \mu_{i-1},$ $1

AB - Let $F$ be a rational function of one complex variable of degree $m\geq 2$. The function $F$ is called simple if for each $z\in \mathbb C\mathbb P^1$ the preimage $P^{-1}\{z\}$ contains at least $m-1$ points. We show that if $F$ is a simple rational function of degree $m\geq 4$ and $F^{\circ l} =G_r\circ G_{r-1}\circ \dots \circ G_1$, $l\geq 1$, is a decomposition of an iterate of $F$ into a composition of indecomposable rational functions, then $r=l$, and there exist M\"obius transformations $\mu_i,$ $1\leq i \leq r-1,$ such that $G_r=F\circ \mu_{r-1},$ $G_i=\mu_{i}^{-1}\circ F \circ \mu_{i-1},$ $1

KW - math.DS

KW - math.CV

M3 - פרסום מוקדם

BT - On iterates of rational functions with maximal number of critical values

ER -