  Using the Schwinger-Keldysh-formalism, reformulated in arXiv:2108.01695 as an
effective field theory in Euclidean anti-de Sitter, we evaluate the one-loop
cosmological four-point function of a conformally coupled interacting scalar
field in de Sitter. Recasting the Witten cosmological correlator as flat space
Feynman integrals, we evaluate the one-loop cosmological four-point functions
in de Sitter space in terms of single-valued multiple polylogarithms. From it
we derive anomalous dimensions and OPE coefficients of the dual conformal field
theory at space-like, future infinity. In particular, we find an interesting
degeneracy in the anomalous dimensions relating operators of neighboring spins.
