Sum formula for Kloosterman sums and fourth moment of the Dedekind zeta-function over the Gaussian number field

Roelof W. Bruggeman, Yoichi Motohashi

We prove the Kloosterman-Spectral sum formula for PSL(2,Z[i])\PSL(2,C), and apply it to derive an explicit spectral expansion for the fourth power moment of the Dedekind zeta funct…