We present a novel mechanism for dark matter (DM) production through domain walls (DWs) formed during inflation. Starting with an introduction to topological defects and their role in cosmology, we focus on the axion field, highlighting concepts such as inflationary diffusion, the misalignment mechanism, and isocurvature perturbations. Our study proposes that DWs reenter the horizon post-inflation, collapse, and generate DM particles. For the QCD axion, this mechanism is tightly constrained by current experiments, but for axion-like particles (ALPs) with fixed initial misalignment, it provides a viable explanation for DM. Future directions include refining the QCD and ALP model and exploring other scalar fields with discrete symmetries as dark matter candidates.
Organized by: Catarina Cosme