Weight $1/2$ multiplier systems for the group $Γ_0^+(p)$ and a geometric formulation
We construct a weight $1/2$ multiplier system for the group $Γ_0^+(p)$, the normalizer of the congruence subgroup $Γ_0(p)$ where $p$ is an odd prime, and we define an analogue of the eta function and Rademacher symbol and relate it to the geometry of edge paths in a triangulation of the upper half plane.
math.NT↗