Related papers: Axion Cosmology with its Scalar Superpartner
Various authors have noted that in particular models, the upper bound on the axion decay constant may not hold. We point out that within supersymmetry, this is a generic issue. For large decay constants, the cosmological problems associated…
Supersymmetric Peccei-Quinn symmetry and string theory predict a complex scalar field comprising a dilaton and an axion. These fields are massless at high energies, but it is known since long that the axion is stabilized in an instanton…
We show that the hybrid inflation is naturally realized in the framework of a supersymmetric axion model, which is consistent with the WMAP observation if the Peccei-Quinn symmetry breaking scale is around 10^{15}GeV. By solving the post…
We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By evaluating the axion potential in the…
We show that the required high quality of the Peccei-Quinn symmetry can be naturally explained in the aligned QCD axion models where the QCD axion arises from multiple axions with decay constants much smaller than the axion window, e.g.,…
We argue that the QCD axion can arise from many aligned axions with decay constants much smaller than the conventional axion window. If the typical decay constant is of {\cal O}{(100)} GeV to 1 TeV, one or more of the axions or saxions may…
The QCD axion cosmology depends crucially on whether the QCD axion is present during inflation or not. We point out that contrary to the standard criterion, the Peccei-Quinn (PQ) symmetry could remain unbroken during inflation, even when…
The mass of the axion and its decay rate are known to depend only on the scale of Peccei-Quinn symmetry breaking, which is constrained by astrophysics and cosmology to be between $10^9$ and $10^{12}$ GeV. We propose a new mechanism such…
The clockwork axion refers to a family of aligned multi-axion models that lead to an exponential hierarchy between the scale of Peccei-Quinn symmetry breaking and the scale of the axion decay constant. The clockworking can bring the…
We show that a supersymmetric axion model naturally induces a hybrid inflation with the waterfall field identified as a Peccei-Quinn scalar. The Peccei-Quinn scale is predicted to be around 10^{15}GeV for reproducing the large-scale density…
It is often the case that scalar fields are produced in the early Universe in the form of coherent oscillation. These scalar fields may have huge abundances and affect the evolution of the Universe. In particular, if the lifetime is long…
We discuss some cosmological aspects of supersymmetric axion models in which the axion scale is radiatively generated in terms of the weak scale and the Planck scale. They include thermal inflation, axions produced by the decay of…
In supersymmetric theories, the presence of axions usually implies the existence of a non-compact, (pseudo)moduli space. In gauge mediated models, the axion would seem a particularly promising dark matter candidate. The cosmology of the…
All generic, calculable models of dynamical supersymmetry breaking have a spontaneously broken $R$ symmetry and therefore contain an $R$ axion. We show that the axion is massive in any model in which the cosmological constant is fine-tuned…
We revisit the cosmological aspects of axion models. In the high-scale inflation scenario, the Peccei-Quinn (PQ) symmetry is likely to be restored during/after inflation. If the curvature of the PQ scalar potential at the origin is smaller…
We have investigated the cosmological scenarios with a four dimensional effective action which is connected with multidimensional, supergravity and string theories. The solution for the scale factor is such that initially universe undergoes…
Complex scalar fields charged under approximate $U(1)$ symmetries appear in well-motivated extensions of the Standard Model. One example is the field that contains the QCD axion field associated with the Peccei-Quinn symmetry; others…
Recently we have proposed a simple hadronic axion model within gauge-mediated supersymmetry breaking. In this paper we discuss various cosmological consequences of the model in great detail. A particular attention is paid to a saxion, a…
We revisit inflationary cosmology of axion models in the light of recent developments on the inflaton decay in supergravity. We find that all the cosmological difficulties, including gravitino, axino overproduction and axionic isocurvature…
We report that the hypothesis that the upper bound on the axion decay constant can be moved up beyond $10^{12}$ GeV in models with a stronger QCD in the early universe is not realized. This proof is possible by studying the superpotential…