Physics Colloquium

Demystifying Graviton Detection

Gravitons are a core prediction of quantum gravity, yet their detection has long been regarded as essentially impossible. We have recently shown, however, that single gravitons can in fact be detected using quantum sensing in macroscopic quantum resonators, in a manner conceptually analogous to the photoelectric detection of photons. In this talk, I will first give a brief overview of recent ideas for testing quantum signatures of gravity in table-top experiments. I will then turn to the detection of individual on-shell gravitons, which represents a conceptually distinct approach. After revisiting the conventional arguments for the impossibility of graviton detection, I will present the key insights that overturn this view, explain the novelties that make detection feasible, and discuss why this possibility has been overlooked until now. Finally, I will show how this experimentally accessible approach could soon open a path to observing gravitons, probing quantum features of gravitational radiation, and testing key predictions of linearized quantum gravity — echoing the early explorations of quantum theory in the early 20th century.

Join via Zoom:
https://caltech.zoom.us/j/84497014003
Meeting ID: 844 9701 4003

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.