Research project Axion astrophysics and cosmology

In a new study, researchers at Stockholm University and the Oskar Klein Centre have found that a theoretically well-motivated extension of the standard description of the strong nuclear interactions could have made the early moments of Big Bang cosmology more tumultuous, leading to a prediction of gravitational waves remarkably consistent with emerging observational hints.

David has been appointed one of the university's four educational ambassadors for 2026 and has been awarded the vice-chancellor's fund for quality development in education. His project aims to develop new forms of continuous assessment. “Generative AI's rapidly improving skills in physical problem solving threaten to make all forms of assignments less effective as educational tools,” says David Marsh.

Dark matter might not need to be made of tiny, lightweight axions after all. This paper shows that much heavier axions, once thought too unstable, could survive to the present day and account for dark matter. Axions, hypothetical particles that barely interact with light, are a primary candidate for dark matter. Scientists believed axions had to be very light, since heavier ones would decay too quickly into photons and disappear. Our new study challenges this view. We propose a new force, similar to the one that forges protons, able to hold together "dark gluons" into stable clumps called glueballs.

EuCAPT is a European consortium for astroparticle theory. It aims to bring together European researchers in theoretical astroparticle physics and cosmology. In early February, David Marsh took over as Vice Director of the consortium. At Fysikum he is a researcher in astroparticle physics and teaches the course Quantum Phenomena and Radiation Physics.