This project explores cosmological aspects of physics beyond the Standard Model from a theoretical perspective while incorporating new experimental results in cosmology, gravitational wave observatories, and large scale structure (LSS) surveys (DESI, Euclid). By analyzing their implications for fundamental physics, the project offers an opportunity to engage with modern theoretical modeling, data analysis techniques, and a range of cutting-edge beyond the Standard Model scenarios, including phase transitions, topological defects, axions, primordial black holes, dark energy, and dark matter.