Title: Pulsating Stars as Laboratories for Axions

Host: Sam Homiller

Abstract: Stars are ideal laboratories for studying new physics that couples weakly with the Standard Model sector, with the extreme stellar interiors enable the efficient production of feebly interacting particles. Stellar observations, including their emission spectra and dynamics, offer new insights into the impact of these particles on stellar evolution. Cepheid variable stars, known for their periodic radial pulsations and roles as cosmic standard candles, are very sensitive to exotic energy loss mechanisms. In this talk, I will introduce stellar observations for new physics searches. I will then discuss how the evolution of pulsating stars, especially during the blue loop phase, serves as a novel probe of axion-like particles. Future observations of heavy Cepheids, together with mass measurements via dynamical methods, open new possibilities for constraining axion parameter space. Finally, I will discuss the effect of other new physics models on pulsating stars, the connection to the Cepheid mass discrepancy, and the broader implications for cosmic distance measurements.