Cosmological and astrophysical probes are emerging as the next frontier of new discoveries in fundamental particle physics. In this talk we will introduce two recent directions bridging physics at largest and smallest scales. In the first half, we will review the recent program of cosmological collider physics, which aims at searching for imprints of new heavy particles and interactions from the large-scale density fluctuations in our universe. In the second half, we will show how the gravitational wave can provide us a unique chance to probe the invisible ambient mass of compact binaries.