This page has the material for lectures on "Non-perturbative physics in the early Universe" for a GGI winter school in 2025.

Topics to be covered, given time:
1. Topological defects

2. Cosmological evolution and observable signals of topological defects

3. Non-topological solitons: Q-balls and axion stars

4. Instantons and vacuum decay 

5. Realisations in strongly coupled theories