 Let "G" be a reductive algebraic group over a number field "K" and let A denote the adeles of "K".The group "G"("K") embeds diagonally in the group "G"(A) by sending "g" in "G"("K") to the tuple ("g""p")"p" in "G"(A) with "g"="g""p" for all (finite and infinite) primes "p".Let "Z" denote the centre of "G" and let ω be a continuous unitary character from "Z"("K") \ Z(A)× to C×.