“…Define j α ; α ∈ R, to be the automorphic factor given by j α (g, z) = e 2iα z,g −1 ·0 , g ∈ G, z ∈ C, (2.1) where here and elsewhere z denotes the imaginary part of the complex number z and ·,· denotes the usual hermitian scalar product on C. Also, let (ρ, τ ) be an equivariant pair [18,14,1,16]. That is, ρ is a G-endomorphism and τ : C → C a smooth compatible mapping such that τ (g.z) = ρ(g) · τ (z) (2.2) for every g ∈ G and z ∈ C. By Γ we denote a uniform lattice of the additive group (C, +) that can be seen as a discrete subgroup of G by the identification…”