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 …

While the QCD axion is often considered to be necessarily light (≲ eV), recent work has
opened a viable and interesting parameter space for heavy axions, which solve both the …

We explore how quantum gravity effects, manifested through the breaking of discrete
symmetry responsible for both dark matter and domain walls, can have observational effects …

Axion-like particles (ALPs) can form a network of cosmic strings and domain walls that
survives after recombination and leads to anisotropic birefringence of the cosmic microwave …

Inspired by the recent determination of the W-boson mass by the CDF collaboration, we
revisit an SO (10) axion model in which a scalar SU (2) L triplet field with zero hypercharge …

The majoron, a neutrinophilic pseudo-Goldstone boson conventionally arising in the context
of neutrino mass models, can damp neutrino free-streaming and inject additional energy …

A bstract An axion-like-particle (ALP) in the post-inflationary scenario with domain wall
number N> 1 can be dark matter if the residual ℤ N symmetry has a small explicit breaking …

A bstract The axion mass receives a large correction from small instantons if the QCD gets
strongly coupled at high energies. We discuss the size of the new CP violating phases …

A bstract We propose two models where a U (1) Peccei-Quinn global symmetry arises
accidentally and is respected up to high-dimensional operators, so that the axion solution to …

A bstract We employ the effective field theory approach to analyze the characteristics of
Euclidean wormholes within axion theories. Using this approach, we obtain non-perturbative …