Periods, Power Series, and Integrated Algebraic Numbers

Abstract

Periods are defined as integrals of semialgebraic functions defined over the rationals. Periods form a countable ring not much is known about. Examples are given by taking the antiderivative of a power series which is algebraic over the polynomial ring over the rationals and evaluate it at a rational number. We follow this path and close these algebraic power series under taking iterated antiderivatives and nearby algebraic and geometric operations. We obtain a system of rings of power series whose coefficients form a countable real closed field. Using techniques from o-minimality we are able to show that every period belongs to this field. In the setting of o-minimality we define exponential integrated algebraic numbers and show that the Euler constant is an exponential integrated algebraic number. Hence they are a good candiate for a natural number system extending the period ring and containing important mathematical constants.

Final version

References in corpus (3)

• Stability under integration of sums of products of real globally subanalytic functions and their logarithms
• Real Homotopy Theory of Semi-Algebraic Sets
• Lebesgue measure theory and integration theory on non-archimedean real closed fields with archimedean value group

Cited by in corpus (1)

• From Cell Decomposition to Motivic Integration, Hensel Minimality, and Point Counting