相关论文: Dynamical axion misalignment with small instantons
We derive lower bounds for the Higgs-curvature coupling from vacuum stability during inflation in three inflationary models: quadratic and quartic chaotic inflation, and Starobinsky-like power-law inflation. In contrast to most previous…
Models of inflation based on axions, which owe their popularity to the robustness against UV corrections, have also a very distinct class of signatures. The relevant interactions of the axion are a non-perturbative oscillating contribution…
We study the cosmological evolution of the QCD axion coupled to hidden photons. For a moderately strong coupling, the motion of the axion field leads to an explosive production of hidden photons by tachyonic instability. We use lattice…
Light scalar and pseudoscalar particles are compelling dark matter candidates, with a vast running experimental program to discover them. Previous studies have shown that these light fields can generate sizable isocurvature perturbations in…
The decay constant of the QCD axion is required by observation to be small compared to the Planck scale. In theories of "natural inflation," and certain proposed anthropic solutions of the cosmological constant problem, it would be…
In implementations of the electroweak scale cosmological relaxation mechanism proposed so far, the effect of the quantum fluctuations of the homogeneous relaxion field has been ignored. We show that they can grow during the classical…
The QCD axion acquires the potential through the non-perturbative effect of the QCD matters around the QCD phase transition. During this period, the direct interaction between the axion and the QCD matters sets in. Focusing on the impact of…
Models of axion inflation are particularly interesting since they provide a natural justification for the flatness of the potential over a super-Planckian distance, namely the approximate shift-symmetry of the inflaton. In addition, most of…
The QCD axion solves the strong CP problem and represents an attractive particle candidate for cold dark matter (CDM). However, quantum fluctuations of the axion field during inflation easily result in large CDM isocurvature perturbations…
The coupling between a pseudo-scalar inflaton and a gauge field leads to an amount of additional density perturbations and gravitational waves (GWs) that is strongly sensitive to the inflaton speed. This naturally results in enhanced GWs at…
We study the post-inflationary dynamics of the Standard Model (SM) Higgs field in the presence of a non-minimal coupling $\xi|\Phi|^2R$ to gravity, both with and without the electroweak gauge fields coupled to the Higgs. We assume a minimal…
We survey observational constraints on the parameter space of inflation and axions and map out two allowed windows: the classic window and the inflationary anthropic window. The cosmology of the latter is particularly interesting;…
The QCD axion is the leading solution to the strong-CP problem, a dark matter candidate, and a possible result of string theory compactifications. However, for axions produced before inflation, symmetry-breaking scales of $f_a \gtrsim…
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…
Particle decay during inflation is studied by implementing a dynamical renormalization group resummation combined with a small Delta expansion. Delta measures the deviation from the scale invariant power spectrum and regulates the infrared.…
We study the dynamics of axion-like fields in F-theory and suggest that they can serve as inflatons in models of natural inflation. The axions arise from harmonic three-forms on the F-theory compactification space and parameterize a complex…
Non-invertible global symmetry often predicts degeneracy in axion potentials and carries important information about the global form of the gauge group. When these symmetries are spontaneously broken they can lead to the formation of stable…
We argue that inflationary dynamics may support a scenario where significant matter-antimatter asymmetry is generated from initially small-scale quantum fluctuations that are subsequently stretched out over large scales. This scenario can…
We consider axions lighter than what their QCD couplings might otherwise suggest. Starting with a $\mathbb{Z}_N$-axion, we introduce a small explicit $\mathbb{Z}_N$ symmetry-breaking coupling between the Standard Model Higgs boson and a…
Composite axions offer a scenario where the axion emerges as a pion-like state, avoiding fine-tuning of elementary scalars and ameliorating the axion quality problem. Despite these advantages, their post-inflationary cosmology remains…