We review the landscape of QCD axion models. Theoretical constructions that extend the
window for the axion mass and couplings beyond conventional regions are highlighted and …

The evidence of the stochastic gravitational-wave background around the nanohertz
frequency range was recently found by worldwide pulsar timing array (PTA) collaborations …

Kination denotes an era in the cosmological history corresponding to an equation of state
$\omega=+ 1$ such that the total energy density of the universe redshifts as the sixth inverse …

We report the results of Phase 1b of the ORGAN experiment, a microwave cavity haloscope
searching for dark matter axions in the 107.42–111.93 μ eV mass range. The search …

Leptogenesis is generally challenging to directly test due to the very high energy scales
involved. In this Letter, we propose a new probe for leptogenesis with cosmological collider …

Recently, an anomalous excess was found in the electronic recoil data collected at the
XENON1T experiment. The excess may be explained by an axionlike particle (ALP) with a …

In the conventional misalignment mechanism, the axion field has a constant initial field value
in the early Universe and later begins to oscillate. We present an alternative scenario where …

Compact stellar objects like supernovae and neutron stars are believed to cool by emitting
axions predominantly via bremsstrahlung (NN→ NN a), pion conversion (π-p+→ N a), and …

We propose a leptogenesis scenario where baryon asymmetry generation is assisted by the
kinetic motion of the Majoron, J, in the process of lepton-number violating inverse decays of …

A bstract We present a QCD axion model where the couplings of the axion to nucleons,
electrons, and muons are naturally suppressed because of the appropriate choice of the …