# Two recent topics in gravitational-wave cosmology: Binary resonance searches and nonlinear memory from cosmic strings

In the first half of this talk, I will discuss how binary systems can be used as

*dynamical detectors of*gravitational waves (GWs)*.*Since the passage of GWs through a binary perturbs the trajectories of the two bodies, we can infer the presence of a GW signal by searching for changes in the binary's orbital parameters. In the presence of a stochastic GW background (SGWB) these changes accumulate over time, causing the binary orbit to execute a random walk through parameter space.