We propose a systematic method for analyzing Rohrlich-type divisor sums for arbitrary congruence subgroups Gamma_0(N). Our main theorem unifies various results from the literature, and its significance is illustrated through the following five applications: (1) the valence formula, (2) a natural generalization of classical Rohrlich's formula to level N, (3) an explicit version of the theorem by Bringmann-Kane-Löbrich-Ono-Rolen, (4) an extension of the generalized Rohrlich formula proposed by Bringmann-Kane, and (5) an alternative proof of the decomposition formula for twisted traces of CM values of weight 0 Eisenstein series. This is a joint work with Daeyeol Jeon, Soon-Yi Kang, and Chang Heon Kim.

Ref. https://arxiv.org/abs/2410.12571