Permutation of values of irrationality measure functions
Number Theory
2026-04-01 v1
Abstract
For an irrational number α∈R we consider its irrationality measure function ψα(t)=1≤q≤t,q∈Zmin∥qα∥. Let α=(α1,…,αn) be n-tuple of pairwise independent irrational numbers. For each t∈R>1 irrationality measure functions ψα1,…,ψαn can be written in an increasing order ψαv1(t)>ψαv2(t)>⋯>ψαvn−1(t)>ψαvn(t). We consider the vector of functions vα(t):R>1→Sn associated to this order and defined as vα(t)=(v1,v2,…,vn−1,vn). Let k(α) be the number of infinitely occurring different values of vα(t). It is known that if k(α)=k we have n≤2k(k+1). At the same time, for k≥3 and n=2k(k+1) there exists an n-tuple α with k(α)=k. In this work we define a k-cyclic permutation π and prove that in the extremal case n=2k(k+1), k(α)=k the set of successive values of vα(t) is an orbit of π.
Cite
@article{arxiv.2507.20416,
title = {Permutation of values of irrationality measure functions},
author = {Victoria Rudykh},
journal= {arXiv preprint arXiv:2507.20416},
year = {2026}
}
Comments
22 pages, 10 figures