English

Beta-conjugates of real algebraic numbers as Puiseux expansions

Number Theory 2011-05-04 v1

Abstract

The beta-conjugates of a base of numeration β>1\beta > 1, β\beta being a Parry number, were introduced by Boyd, in the context of the R\'enyi-Parry dynamics of numeration system and the beta-transformation. These beta-conjugates are canonically associated with β\beta. Let β>1\beta > 1 be a real algebraic number. A more general definition of the beta-conjugates of β\beta is introduced in terms of the Parry Upper function fβ(z)f_{\beta}(z) of the beta-transformation. We introduce the concept of a germ of curve at (0,1/β)C2(0,1/\beta) \in \mathbb{C}^{2} associated with fβ(z)f_{\beta}(z) and the reciprocal of the minimal polynomial of β\beta. This germ is decomposed into irreducible elements according to the theory of Puiseux, gathered into conjugacy classes. The beta-conjugates of β\beta, in terms of the Puiseux expansions, are given a new equivalent definition in this new context. If β\beta is a Parry number the (Artin-Mazur) dynamical zeta function ζβ(z)\zeta_{\beta}(z) of the beta-transformation, simply related to fβ(z)f_{\beta}(z), is expressed as a product formula, under some assumptions, a sort of analog to the Euler product of the Riemann zeta function, and the factorization of the Parry polynomial of β\beta is deduced from the germ.

Keywords

Cite

@article{arxiv.1105.0574,
  title  = {Beta-conjugates of real algebraic numbers as Puiseux expansions},
  author = {Jean-Louis Verger-Gaugry},
  journal= {arXiv preprint arXiv:1105.0574},
  year   = {2011}
}