On symmetries of roots of rational functions and the classification of rational function solutions of functional equations arising from multiplication of quantum integers with prime semigroup supports

• Published in: Aequationes mathematicae 2018-12, Vol.92 (6), p.1001-1035
• Main Author: Nguyen, Lan
• Format: Article
• Language: English
• Subjects: Analysis; Classification; Coefficients; Combinatorics; Cybernetics; Functional equations; Integers; Mathematical analysis; Mathematics; Mathematics and Statistics; Multiplication; Number theory; Polynomials; Rational functions
• ISSN: 0001-9054; 1420-8903
• DOI: 10.1007/s00010-018-0607-y

The study of quantum integers and their operations is closely related to the studies of symmetries of roots of polynomials and of fundamental questions of decompositions in Additive Number Theory. In his papers on quantum arithmetics, Melvyn Nathanson raises the question of classifying solutions of functional equations arising from the multiplication of quantum integers, starting with polynomial solutions and then generalizing to rational function solutions. The classification of polynomial solutions with fields of coefficients of characteristic zero and support base P has been completed. In a paper concerning the Grothendieck group associated to the collection of polynomial solutions, Nathanson poses a problem which asks whether the set of rational function solutions strictly contains the set of ratios of polynomial solutions. It is now known that there are infinitely many rational function solutions Γ with fields of coefficients of characteristic zero not constructible as ratios of polynomial solutions, even in the purely cyclotomic case, which is the case most similar to the polynomial solution case. The classification of polynomial solutions is thus not sufficient, in essential ways, to resolve the classification problem of all rational function solutions with fields of coefficients of characteristic zero. In this paper we study symmetries of roots of rational functions and the classification of the important class-the last and main obstruction to the classification problem-of rational function solutions, the purely cyclotomic, purely nonrational primitive solutions with fields of coefficients of characteristic zero and support base P , which allows us to complete the classification problem raised by Nathanson.