Using stars as natural laboratories for fundamental physics is an idea with deep roots, but recent years have seen a dynamic resurgence in this approach. In this talk, we will explore how stellar observations - both historical and cutting-edge - are shedding light on axions and other feebly interacting particles. By tracing the evolution of these ideas, from classic arguments to modern...
Pseudo-scalar axions are ubiquitous in high-energy theory, and so are their scalar partners, here called ‟dilatons”, that dynamicalise the corresponding gauge couplings. In this talk, I will discuss the cosmology of dilatons and axions, focussing on the impact of dilaton phase transitions. First, I will show how cosmological dilaton phase transitions can lead to the trapping and compression of...
