| Abstract: In this talk, I will describe two non-thermal classical mechanism to form strings in the early and late universe, amusingly analogous to vortex formations in superconductors and superfluids. These new mechanisms lead to burst of string production, leaving unique signatures in gravitational wave detectors. I will mainly discuss a phenomenon we call the "string bosenova", where gauged strings can form inside vector superradiance clouds around spinning black holes. I will also discuss briefly some new results where we discover periodic string formation in the simplest systems with a global U(1) symmetry in the early universe. This leads to periodic gravitational wave bursts, which could show up in the gravitational wave spectrum as a forest of peaks. If there is time, I will comment on how this affects dark photon and axion dark matter production, and possibly baryogenesis. Link to the Event Video |