Fourier analysis of many-body transition amplitudes and states

Abstract: We apply the Fourier transform over the symmetric group $S_N$ to the set of multiparticle transition amplitudes arising from the permutations of $N$ identical particles. This allows us to analyse the counting statistics at the output of multiparticle and multimode interference setups in terms of contributions from irreducible symmetry types. We apply our formalism to the interference of partially distinguishable bosons and fermions, whose state can also be submitted to Fourier analysis, and to the determination of suppressed transitions for states of a given symmetry type.