Abstract:
We study the number $\#_n^\mathbb R$ of real rational degree $n$ functions (considered up to a linear fractional transformation of the independent variable) with a given set of $2n-2$ distinct real critical values. We present a combinatorial interpretation of these numbers and provide exact and asymptotic enumeration results for certain particular cases.
Key words and phrases:Real rational functions; real critical values; chord diagrams; enumeration.