On sufficient density conditions for lattice orbits of relative discrete series [article]

Ulrik Enstad, Jordy Timo van Velthoven
2021 arXiv   pre-print
This note provides new criteria on a unimodular group G and a discrete series representation (π, ℋ_π) of formal degree d_π > 0 under which any lattice Γ≤ G with vol(G/Γ) d_π≤ 1 (resp. vol(G/Γ) d_π≥ 1) admits g ∈ℋ_π such that π(Γ) g is a frame (resp. Riesz sequence). The results apply to all projective discrete series of exponential Lie groups.
arXiv:2112.05502v1 fatcat:y25b74hb7zdo3p4yoa5zqmfkw4