“…Moreover, the dual basis is given by { e inλ (φ(λ)) −1 √ 2π } n∈Z , and then S n (t) = E(x t z n ) = sin(π(t−n)) π(t−n) , and as μ is equivalent to the restriction of the ordinary Lebesgue measure on [−π, π], one may take the operator T defined by the kernel: k(t, λ) = e itλ 1 [−π,π] (λ). Finally, we recall that in this case, the condition on μ of being absolutely continuous with respect to the Lebesgue measure is necessary, as it was proved in [19].…”