COSMOLOGY OF THE QCD AXION: FROM THERMAL TO INFLATIONARY PRODUCTION (Alessio Notari, Universitat de Barcelona)

Quando:
Gennaio 1, 1970@1:00 am–1:00 am
1970-01-01T01:00:00+01:00
1970-01-01T01:00:00+01:00
Dove:
Aula 501

Seminario Fisica Teorica

The axion is a hypothetical particle that could explain the absence of CP violation in QCD and has a very rich cosmological phenomenology.
In particular a population of thermally produced axions is expected to exist, in addition to a cold dark matter population. I discuss a new conservative bound on the axion mass, from production in the early universe from scattering with pions. In addition I will show that to exploit the reach of upcoming cosmological surveys, non-perturbative calculations above the QCD crossover are needed. Moreover I will also review production from other Standard Model particles (quarks, leptons).
Then, I will discuss the axion cold dark matter population, showing that its abundance depends on non-trivial evolution during primordial inflation.
Finally I will discuss the non-standard case of a heavy QCD axion, which could give rise to a detectable gravitational wave signal at Pulsar Timing Arrays or at interferometers.

Per connettersi a zoom:

https://infn-it.zoom.us/j/93341311520?pwd=RklTcFFVWjdtUzR5TUZKM3V1TjJiQT09