We decompose the space of nearly holomorphic Hilbert–Siegel automorphic
forms as representations of the adele group under certain assumptions.
We also give an application for classical holomorphic Hilbert–Siegel
modular forms. In particular, we show the surjectivity of the global Siegel
operator
for certain congruence subgroups with large weights.
Keywords
Siegel modular forms, Eisenstein series, nearly holomorphic
modular forms