Equivariant Modular Functions and Quantizations of Continued Fractions

Abstract

We show that, in addition to the quantizations of the rational numbers discovered by Morier-Genoud and Ovsienko, there exist a pair of conjugate representations of the modular group and the corresponding equivariant maps with respect to these representations. We discuss some specializations of these quantizations and discuss its connection to Dyer's outer automorphism and the associated involution Jimm of the real line.