Elliptic Units Above Fields With Exactly One Complex Place

Abstract

In this work we explore the construction of abelian extensions of number fields with exactly one complex place using multivariate analytic functions in the spirit of Hilbert's 12th problem. To this end we study the special values of the multiple elliptic Gamma functions introduced in the early 2000s by Nishizawa following the work of Felder and Varchenko on Ruijsenaars' elliptic Gamma function. We construct geometric variants of these functions enjoying transformation properties under an action of $\mathrm{SL}_{d}(\mathbb{Z})$ for $d \geq 2$. The evaluation of these functions at points of a degree $d$ field $\mathbb{K}$ with exactly one complex place following the scheme of a recent article by Bergeron, Charollois and Garc\'ia (arXiv:2311.04110) seems to produce algebraic numbers. More precisely, we conjecture that such infinite products yield algebraic units in abelian extensions of $\mathbb{K}$ related to conjectural Stark units and we provide numerical evidence to support this conjecture for cubic, quartic and quintic fields.