A Kohnen-Zagier Formula in Level 1
Abstract
In 1985 Kohnen used the Shimura correspondence to prove a general formula relating the coefficients of half-integral weight modular forms of level $ 4N $ transforming with respect to the theta multiplier to central values of $ L $-functions for twists of newforms of level $ N $. This generalized previous work with Zagier. In this paper, we prove a Kohnen-Zagier type formula using Yang's Shimura correspondence for powers of the eta multiplier in level $ 1 $, relating the coefficients of half-integral weight modular forms to central values of $ L $-functions for twists of newforms of level $ 6 $. To do so we develop some of the theory of modular forms transforming with respect to powers of the eta multiplier and introduce Shintani lifts of level $ 6 $, with Fourier coefficients given in terms of cycle integrals.
Related
- Zagier's 2-3-2 formula for multiple Eisenstein series
- Jacquet-Zagier treatment of the beyond endoscopy trace formula for GL2
- Tree Lattices and the Neumann-Zagier conjecture
- Value-distribution of Euler--Zagier type multiple zeta-functions with identical arguments on the critical line
- Weighted Generalizations of Zagier's Phenomenon
BibTeX
@misc{williams2026kohnenzagier,
title = {{A Kohnen-Zagier Formula in Level 1}},
author = {Clayton Williams},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.38051},
eprint = {2610.38051},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.38051},
}
RIS
TY - UNPB
TI - A Kohnen-Zagier Formula in Level 1
AU - Clayton Williams
PY - 2026
DA - 2026/10/27
PB - arXiv
DO - 10.48550/arxiv.2610.38051
UR - https://arxiv.org/abs/2610.38051
AB - In 1985 Kohnen used the Shimura correspondence to prove a general formula relating the coefficients of half-integral weight modular forms of level $ 4N $ transforming with respect to the theta multiplier to central values of $ L $-functions for twists of newforms of level $ N $. This generalized previous work with Zagier. In this paper, we prove a Kohnen-Zagier type formula using Yang's Shimura correspondence for powers of the eta multiplier in level $ 1 $, relating the coefficients of half-integral weight modular forms to central values of $ L $-functions for twists of newforms of level $ 6 $. To do so we develop some of the theory of modular forms transforming with respect to powers of the eta multiplier and introduce Shintani lifts of level $ 6 $, with Fourier coefficients given in terms of cycle integrals.
ER -