Skip to content

On closed rational functions in several variables

A. P. Petravchuk, O. G. Iena

math.RAarXiv:math/0701588

Abstract

Let k be an algebraically closed field of characteristic zero. An element F from k(x1,...,xn) is called a closed rational function if the subfield k(F) is algebraically closed in the field k(x1,...,xn). We prove that a rational function F=f/g is closed if f and g are algebraically independent and at least one of them is irreducible. We also show that the rational function F=f/g is closed if and only if the pencil af+bg contains only finitely many reducible hypersurfaces. Some sufficient conditions for a polynomial to be irreducible are given.

Create a lesson