TPPC 2024 Kick-off meeting

The QCD axion is a compelling target for physics beyond the Standard Model which offers also a characteristic imprint in the Early Universe as a hot relic. In this talk we present a state-of-the-art bound on the QCD axion from Cosmology by confronting momentum-dependent Boltzmann equations against up-to-date measurements of the CMB – including ground-based telescopes – and abundances from BBN. We conclude presenting forecasts using dedicated likelihoods for future cosmological surveys and recent non-perturbative computations at the crossover from lattice QCD.

I will present two complementary ideas to look for sub-MeV dark matter: superfluid helium-4 and anti-ferromagnetic materials. I will discuss advantages and possible difficulties, and argue that a prominent theoretical tool to tackle these problems should be Goldstone’s theorem for spontaneously broken spacetime symmetries.

In this talk, three topics concerning aspects of cosmology and particle physics will be discussed: 1) primordial black hole production during the early universe; 2) higher-order computations of cosmological correlators in non-single-clock inflation, and 3) QCD axion dynamics and the role of gravitational anomalies.