English

Modular forms of half-integral weights on SL(2,Z)

Number Theory 2011-10-11 v1

Abstract

In this paper, we prove that, for an integer rr with (r,6)=1(r,6)=1 and 0<r<240<r<24 and a nonnegative even integer ss, the set {\eta(24\tau)^rf(24\tau):f(\tau)\in M_s(1)} is isomorphic to S_{r+2s-1}^{\text{new}}(6,-(\frac8r),-(\frac{12}r))\otimes(\frac{12}\cdot) as Hecke modules under the Shimura correspondence. Here Ms(1)M_s(1) denotes the space of modular forms of weight ss on Γ0(1)=SL(2,Z)\Gamma_0(1)=\mathrm{SL}(2,\Z), S2knew(6,ϵ2,ϵ3)S_{2k}^{\text{new}}(6,\epsilon_2,\epsilon_3) is the space of newforms of weight 2k2k on Γ0(6)\Gamma_0(6) that are eigenfunctions with eigenvalues ϵ2\epsilon_2 and ϵ3\epsilon_3 for Atkin-Lehner involutions W2W_2 and W3W_3, respectively, and the notation (12)\otimes(\frac{12}\cdot) means the twist by the quadratic character 12)\frac{12}\cdot). There is also an analogous result for the cases (r,6)=3(r,6)=3.

Keywords

Cite

@article{arxiv.1110.1810,
  title  = {Modular forms of half-integral weights on SL(2,Z)},
  author = {Yifan Yang},
  journal= {arXiv preprint arXiv:1110.1810},
  year   = {2011}
}

Comments

57 pages

R2 v1 2026-06-21T19:17:25.823Z