Axions in Japan

Session

Parallel session - CMB

12 Nov 2025, 14:00

Lecture Hall (Kavli IPMU)

26. Axion/ ALP scenario with high scale inflation

Dan Kondo

12/11/2025, 14:00

Considering that next generation CMB experiments like LiteBIRD and CMBS4 will probe the gravitational wave from high scale inflation via the observation of B-mode. We study the DFSZ-like GUT scenario where QCD axion and ALP exist in the evolution of the universe. In the conventional DFSZ scenario, since the domain wall number is larger than one, axion DM with PQ scale lower than inflation...

27. Circularly polarized radiation from Axion-Photon conversion and CMB V-mode measurements

Ashu Kushwaha

12/11/2025, 14:20

In the presence of a background magnetic field, axions or axion-like particles (ALPs) can be resonantly converted to photons when their mass is nearly equal to the effective photon mass. In this paper, we propose a novel method to constrain the parameter space of ALPs by investigating the resulting imprints of axion-photon conversion in the cosmic microwave background (CMB) observations. We...

28. Improved cosmological constraints on axion-lepton interactions

Adam Gomułka

12/11/2025, 14:40

We present improved cosmological constraints on lepton couplings to thermally produced axion-like particles (ALPs). These interactions can affect the expansion history of the early Universe and leave distinctive signatures on the Cosmic Microwave Background (CMB) and Baryon Acoustic Oscillations (BAO). We compute precise ALP energy spectra by numerically solving the full Boltzmann equation,...