Height gaps for coefficients of D-finite power series

Speaker: Khoa D. Nguyen

Date: Mon, Sep 26, 2022

Location: PIMS, University of Lethbridge

Conference: Lethbridge Number Theory and Combinatorics Seminar

Subject: Mathematics, Combinatorics, Number Theory

Class: Scientific

Abstract:

Khoa D. Nguyen (University of Calgary, Canada)

A power series f(x1,,xm)C[[x1,,xm]] is said to be D-finite if all the partial derivatives of f span a finite dimensional vector space over the field C(x1,,xm). For the univariate series f(x)=anxn, this is equivalent to the condition that the sequence (an) is P-recursive meaning a non-trivial linear recurrence relation of the form:
Pd(n)an+d++P0(n)an=0

where the Pi's are polynomials. In this talk, we consider D-finite power series with algebraic coefficients and discuss the growth of the Weil height of these coefficients. This is from a joint work with Jason Bell and Umberto Zannier in 2019 and a more recent work in June 2022.