Intersection multiplicities of Noetherian functions

TL;DR

This paper develops an effective method to bound the intersection multiplicity of Noetherian functions at non-isolated zeros, based on degrees and dimensions, addressing a key problem in algebraic geometry.

Contribution

It introduces a procedure to effectively bound the multiplicity of non-isolated intersections of Noetherian functions using degrees and dimensions.

Findings

Provides an explicit upper bound for intersection multiplicities

Applies to foliations defined by polynomial vector fields

Addresses a longstanding problem in algebraic geometry

Abstract

We provide a partial answer to the following problem: \emph{give an effective upper bound on the multiplicity of non-isolated common zero of a tuple of Noetherian functions}. More precisely, consider a foliation defined by two commuting polynomial vector fields $V_1,V_2$ in $\C^n$, and $p$ a nonsingular point of the foliation. Denote by $\cL$ the leaf passing through $p$, and let $F,G\in\C[X]$ be two polynomials. Assume that $F\onL=0,G\onL=0$ have several common branches. We provide an effective procedure which allows to bound from above multipllicity of intersection of remaining branches of $F\onL=0$ with $G\onL=0$ in terms of the degrees and dimensions only.