Constructibility of the set of polynomials with a fixed Bernstein-Sato polynomial: an algorithmic approach

摘要

Let n and d be positive integers, led k be a field and led P(n, d; k)be the space of the non-zero polynomials in variables of degree at most d with coefficients in k. Let B(n ,d) be the set of the Bernstein-Sato polynomials of all polynomials in P(n,d; k)as k varies over all fields of characteristics 0. G. Lyubeznik proved that B(n ,d)is a finite set and asked if, for a fixed k, the set of the polynomials corresponding to each element of B(n, d) is a constructible subset of P(n,d; k). In this paper we give an affirmative answer to Lyubeznik's question by showing that The set in question is indeed constructible and defined over Q, i.e. its defining equations Are the same for all fields k.