Polynomials in one variable and ranks of certain tangent maps
arXiv:1010.0282
Abstract
We study a map that sends a monic degree n complex polynomial f(x) without multiple roots to the collection of n values of its derivative at the roots of f(x). We give an answer to a question posed by Ju.S. Ilyashenko.
Remark 3.5 has been corrected/updated