Correlators Are Simpler than Wave Functions.

Recent works reveal a simplicity in equal-time correlators absent from wave functions. We show that it follows from the fact that correlators are full spacetime integrals rather than half-spacetime integrals as for the wave function. This makes striking properties manifest: some wave function singularities are absent, factorization simplifies, and around every pole the Laurent expansion has a vanishing first subleading term. Near the total-energy pole, the expansion to second order is generated by a differential operator on scattering amplitudes.