Snowmass 2021 Letters of Interest

Snowmass 2021 is a planning exercise of the particle physics community that provides community input to the Particle Physics Project Prioritization Panel (P5), which will develop a strategic plan for US particle physics over the next decade. The Cosmic Frontier science area includes topics where astronomy and astrophysics intersect with particle physics, including dark matter, dark energy, gravitational waves, and black holes. Previous iterations of Snowmass and P5 have been important for major ground-based astronomical facilities and experiments such as the Vera C. Rubin Observatory, the Dark Energy Survey (DES), the Dark Energy Spectroscopic Instrument (DESI), and cosmic microwave background experiments.

The following Snowmass 20201 Letters of Interest (LOIs) discuss Cosmic Frontiers scientific topics where Extremely Large Telescopes and the US ELT Program will play important roles. This list is likely incomplete; if you know of other relevant LOIs that are not listed here, please write to