"Probing General Relativity using the spin of light"

Presented by Dr. Francesco Serra, Post Doctoral Researcher from Johns Hopkins University

I will present a new type of gyroscope that measures rotation through its effect on the polarization of light. Unlike conventional Sagnac interferometers, where vibration-induced phase shifts dominate the noise, this setup rejects vibrational noise since the rotation effect is independent of the frequency of light. By storing light for long durations in superconducting radio-frequency cavities, the gyroscope achieves a precision scaling with storage time that is inaccessible to other approaches. This opens the door to a ground-based measurement of the Lense–Thirring frame-dragging effect predicted by General Relativity around Earth. A key challenge for such a measurement is referencing the gyroscope to an inertial coordinate frame, for instance that defined by distant quasars. To address this challenge, I will outline strategies for mitigating systematic effects from atmospheric variations.

Bring your lunch to enjoy during the seminar.