Images of Maass-Poincar\'e series in the lower half-plane
  In this note we extend integral weight harmonic Maass forms to functions defined on the upper and lower half-planes using the method of Poincar\'e series. This relates to Rademacher's "expansion of zero" principle, which was recently employed by Rhoades to link mock theta functions and partial theta functions. 
Nickolas Andersen, Kathrin Bringmann, and Larry Rolen
math.NT