With the establishment and maturation of the experimental programs searching for new
physics with sizeable couplings at the LHC, there is an increasing interest in the broader …

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 …

Axions and other very light axion-like particles appear in many extensions of the Standard
Model, and are leading candidates to compose part or all of the missing matter of the …

Two of the most pressing questions in physics are the microscopic nature of the dark matter
that comprises 84% of the mass in the Universe and the absence of a neutron electric dipole …

This article reviews recent developments in tests of fundamental physics using atoms and
molecules, including the subjects of parity violation, searches for permanent electric dipole …

A bstract We explore whether the axion which solves the strong CP problem can naturally be
much lighter than the canonical QCD axion. The\({Z} _ {\mathcal {N}}\) symmetry proposed …

We point out two ways to search for low-mass axion dark matter using cosmic microwave
background (CMB) polarization measurements. These appear, in particular, to be some of …

We show that dark matter can be accounted for by an axion that solves the strong CP
problem, but is much lighter than usual due to a Z Script N symmetry. The whole mass range …

In the scenario in which QCD axion dark matter is produced after inflation, the Universe is
populated by large inhomogeneities on very small scales. Eventually, these fluctuations will …

Axions and axionlike particles (ALPs) are some of the most popular candidates for dark
matter, with several viable production scenarios that make different predictions. In the …