Snowmass 2021 White Paper: Tabletop experiments for infrared quantum gravity

Understand

Progress in the quantum readout and control of mechanical devices from single atoms to large masses may enable a first generation of experiments probing the gravitational interaction in the quantum regime, conceivably within the next decade.

• In this Snowmass whitepaper, we briefly outline the possibilities and challenges facing the realization of these experiments.
• In particular, we emphasize the need for detailed theories of modifications to the usual effective QFT of gravitons in the infrared regime $E/L^3 \ll m_{\rm Pl}/\ell_{\rm Pl}^3$ in which these experiments operate, and relations to possible UV completions.