Higher pullbacks of modular forms on orthogonal groups
arXiv:1910.11681 · doi:10.1515/forum-2020-0066
Abstract
We apply differential operators to modular forms on orthogonal groups to construct infinite families of modular forms on special cycles. These operators generalize the quasi-pullback. The subspaces of theta lifts are preserved; in particular, the higher pullbacks of the lift of a (lattice-index) Jacobi form are theta lifts of partial development coefficients of . For certain lattices of signature (2, 2) and (2, 3), for which there are interpretations as Hilbert-Siegel modular forms, we observe that the higher pullbacks coincide with differential operators introduced by Cohen and Ibukiyama.
20 pages