Amplitudes meet Effective Field Theory: a journey from particles, black holes, to the cosmos

Quantum field theory and gravity form the foundation of modern theoretical physics. These play central roles for experiments such as the Large Hadron Collider, cosmic microwave background detections, and gravitational-wave observatories. In this talk, I will describe how to find new structures and applications in field theory and gravity by harnessing tools from scattering amplitudes and effective field theory. First, I will present a surprising (non)renormalization structure in beyond the Standard Model physics. Second, I will give an on-shell perspective of spontaneous symmetry breaking that unifies various kinds of Goldstone bosons. I will also incorporate the theory of inflation into this picture. Lastly, I will describe how these ideas are now pushing the state of the art for calculations of the binary black hole inspiral problem directly relevant for current and future gravitational-wave detectors.