Consider a discrete group G and a bounded self-adjoint convolution operator T on l2 (G); let σ (T) be the spectrum of T. The spectral theorem gives a unitary isomorphism U between l2 (G) and a direct ...
Let μn be a sequence of discrete measures on the unit circle T = ℝ/ℤ with μn (0) = 0, and μn ((-δ,δ)) → 1, as n → ∞. We prove that the sequence of convolution operators (f ⁕ μn)(x) is strong sweeping ...