| Abstract: Axion-like particles (ALPs) are a compelling candidate for dark matter (DM). Their production is associated with the formation of a string-wall network. If stable, this system must annihilate, producing gravitational waves and non-relativistic ALPs. In my talk, I will show that these gravitational waves, when produced at temperatures below 100 eV, could be detected by future cosmological probes for ALPs with mass from 10^−16 to 10^+6 eV, opening a window on ALP DM with arbitrary small couplings to the Standard Model. Link to the Event Video |