  Light-ray operators naturally arise from integrating Einstein equations at
null infinity along the light-cone time. We associate light-ray operators to
physical detectors on the celestial sphere and we provide explicit expressions
in perturbation theory for their hard modes using the steepest descent
technique. We then study their algebra in generic 4-dimensional QFTs of
massless particles with integer spin, comparing with complexified Cordova-Shao
algebra. For the case of gravity, the Bondi news squared term provides an
extension of the ANEC operator at infinity to a shear-inclusive ANEC, which as
a quantum operator gives the energy of all quanta of radiation in a particular
direction on the sky. We finally provide a direct connection of the action of
the shear-inclusive ANEC with detector event shapes and we study infrared-safe
gravitational wave event shapes produced in the scattering of massive compact
objects, computing the energy flux at infinity in the classical limit at
leading order in the soft expansion.

High Energy Physics - Theory