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 …

There is a guaranteed background of stochastic gravitational waves produced in the thermal
plasma in the early universe. Its energy density per logarithmic frequency interval scales …

The LHAASO Collaboration detected the gamma ray burst GRB 221009A at energies above
500 GeV with a tail extending up to 18 TeV, whose spectral analysis has presently been …

We consider a gauge-singlet complex scalar field Φ with a global U (1) symmetry that is
spontaneously broken at some high energy scale f a. As a result, the angular part of the Φ …

We offer a pedagogical introduction to axion-like particles (ALPs) as far as their relevance
for high-energy astrophysics is concerned, from a few MeV to 1000 TeV. This review is self …

In these notes I try to introduce the reader to the topic of axions: their theoretical motivation
and expected phenomenology, their role in astrophysics and as dark matter candidate, and …

A bstract We revisit the ALP miracle scenario where the inflaton and dark matter are unified
by a single axion-like particle (ALP). We first extend our previous analysis on the inflaton …

We present a proposal to search for QCD axions with mass in the 200 μ eV range, assuming
that they make a dominant component of dark matter. Due to the axion–electron spin …