New opportunities in axion cosmology
Tsung-Dao Lee Institute/N6F-N600 - Lecture Room
Tsung-Dao Lee Institute
Host: Gwenael Giacinti
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Abstract:
Axion-like particles offer a unified framework to address both dark matter (DM) and dark energy (DE). In this talk, I will present recent progress in two complementary directions. First, I will discuss aquintessence axion model for dynamical dark energy, motivated by new Baryon Acoustic Oscillation data from DESI and Cosmic Microwave Background (CMB) observations. This model favors a sub-Planckian axion decay constant and a relatively large mass, naturally avoiding the quality problem while staying consistent with theoretical expectations. It may also help explain the recently reported non-zero rotation of the CMB polarization angle, pointing at broader cosmological implications. Second, I will turn to indirect detection strategies for axions. Using a Gaussian Process Reconstruction of the reionization history from low-multipole CMB data, we derive constraints on the lifetime of MeV-scale axions through their energy injection into the ionized intergalactic medium. This leads to the strongest bounds to date on the axion–photon coupling in this mass window. Based on 2504.17638, 2506.19096, 2507.03535.
Biography:
My research activities encompass a wide range of topics within particle astrophysics, including investigations into dark matter, dark energy, and black holes. My primary focus lies in exploring the intriguing role of light bosons as potential dark matter candidates, addressing the Hubble tension, and unraveling the implications of black hole physics in cosmology.
