摘要
Let S⊂ℝ d be a bounded subset with positive Lebesgue measure. The Paley-Wiener space associated to S, PW S , is defined to be the set of all square-integrable functions on ℝ d whose Fourier transforms vanish outside S. A sequence (x j :j∈ℕ) in ℝ d is said to be a Riesz-basis sequence for L 2(S) (equivalently, a complete interpolating sequence for PW S ) if the sequence (e-i谩xj,·帽:j 脦 \mathbb N)(e^{-i\langle x_{j},\cdot \rangle }:j\in \mathbb {N}) of exponential functions forms a Riesz basis for L 2(S). Let (x j :j∈ℕ) be a Riesz-basis sequence for L 2(S). Given λ>0 and f∈PW S , there is a unique sequence (a j ) in ℓ 2 such that the function Il(f)(x):=氓j 脦 \mathbb Naje-l||x-xj||22, x 脦 \mathbb Rd,I_\lambda(f)(x):=\sum_{j\in \mathbb {N}}a_je^{-\lambda \|x-x_j\|_2^2},\quad x\in \mathbb {R}^d,