English

Locally harmonic Maa{\ss} forms of positive even weight

Number Theory 2026-01-21 v4

Abstract

We twist Zagier's function fk,Df_{k,D} by a sign function and a genus character. Assuming weight 0<k2(mod4)0 < k \equiv 2 \pmod{4}, and letting DD be a positive non-square discriminant, we prove that the obstruction to modularity caused by the sign function can be corrected obtaining a locally harmonic Maa\ss form or a local cusp form of the same weight. In addition, we provide an alternative representation of our new function in terms of a twisted trace of modular cycle integrals of a Poincar\'e series due to Petersson.

Keywords

Cite

@article{arxiv.2104.03127,
  title  = {Locally harmonic Maa{\ss} forms of positive even weight},
  author = {Andreas Mono},
  journal= {arXiv preprint arXiv:2104.03127},
  year   = {2026}
}

Comments

17 pages, no figures