With their solo show “In the Absence of Evidence,” opening at Galerie Liusa Wang Paris, artist duo Quadrature revisit the boundary between science and fiction: C.R.E.D.O. (Cosmic Radio Engine for Delusional Observations), for example, is a 2020 sound installation that channels Pulsar signals, received via an on-site radio dish, into an otherworldly score. “The raw signals serve as input data for a neural network trained on human theories on aliens,” state the artists. The composition is the network trying to find E.T. messages in the noise.