String theory predicts an axiverse of ultralight axions whose effects on CMB polarization, matter power spectrum, and black hole superradiance can be probed by future astrophysical experiments.
hub Canonical reference
Solutions to the strong CP problem in a world with gravity
Canonical reference. 100% of citing Pith papers cite this work as background.
17
Pith papers citing it
Background
100% of classified citations
abstract
We examine the sensitivity of several solutions of the strong-CP problem to violations of global symmetries by Planck scale physics. We find that the Peccei-Quinn solution is extremely sensitive to U(1)_PQ violating operators of dimension less than 10. We construct models in which the PQ symmetry is protected by gauge symmetries to the requisite level.
hub tools
citation-role summary
background 13
citation-polarity summary
roles
background 13polarities
background 13representative citing papers
A 5D holographic QCD axion model identifies bulk modes for the axion and eta prime, traces the quality problem to insufficient compositeness, and finds the physical axion mostly in the bulk gauge field when quality is high.
A discrete gauge symmetry protecting the axion induces a large effective mass during inflation via a gauge-invariant PQ-violating operator, suppressing isocurvature fluctuations and addressing both quality and isocurvature issues.
A mirror GUT model confines dynamically to produce a heavy axion solving the strong CP problem while allowing observable EDMs and a rich hidden sector.
The EIC can probe invisible pseudoscalar meson decays down to branching ratios of 10^{-8} and invisibly decaying ALPs with couplings up to 10^5 GeV for masses 0.1-2 GeV.
In asymptotically safe gravity, dimension-five couplings of ultralight scalar dark matter to gauge field strengths vanish and are not generated perturbatively.
Nelson-Barr mechanism yields ultralight scalar dark matter inducing time-periodic variation in CKM matrix elements, distinguishable from QCD axion and detectable via nuclear clocks.
Special embedding of the composite axion and QCD gauge groups into a larger product gauge group reduces the domain wall number to unity and induces a controlled bias term from UV instantons that destabilizes the walls.
A chiral U(1) gauge symmetry generates an accidental Peccei-Quinn symmetry broken by mirror QCD, solving the strong CP problem without a light axion while supplying WIMP dark matter, stochastic gravitational waves, and LHC-testable colored pNGBs.
In gauged U(1) completions enabling high-quality axion dark matter, cosmic string loops generate a stochastic gravitational wave background with an infrared break frequency that exceeds foregrounds above 10^14 GeV breaking scales and offers a probe at interferometers.
Spontaneous wash-in leptogenesis in Type II Seesaw with Majoron pNGB background enables baryon asymmetry generation alongside dark matter cogenesis for specific v_T, v_sigma and m_j ranges.
Kinetic mixing between hidden-sector fluxes and QCD's topological sector shifts the effective theta angle and produces nonzero <G tilde G>.
Solar axion-like particles up to 5.5 MeV produce off-axis MeV photons via two-body decay, enabling new space and terrestrial searches that could probe g_aγ down to 10^{-12} GeV^{-1}.
Review classifies QCD axion models extending the standard mass-coupling window and updates bounds from cosmology, astrophysics, and experiments.
citing papers explorer
-
String Axiverse
String theory predicts an axiverse of ultralight axions whose effects on CMB polarization, matter power spectrum, and black hole superradiance can be probed by future astrophysical experiments.
-
The Holographic QCD Axion in Five Dimensions
A 5D holographic QCD axion model identifies bulk modes for the axion and eta prime, traces the quality problem to insufficient compositeness, and finds the physical axion mostly in the bulk gauge field when quality is high.
-
High-Quality Axion Dark Matter without Isocurvature Problem
A discrete gauge symmetry protecting the axion induces a large effective mass during inflation via a gauge-invariant PQ-violating operator, suppressing isocurvature fluctuations and addressing both quality and isocurvature issues.
-
Heavy Axion from a Confining Mirror GUT
A mirror GUT model confines dynamically to produce a heavy axion solving the strong CP problem while allowing observable EDMs and a rich hidden sector.
-
Braking protons at the EIC: from invisible meson decay to new physics searches
The EIC can probe invisible pseudoscalar meson decays down to branching ratios of 10^{-8} and invisibly decaying ALPs with couplings up to 10^5 GeV for masses 0.1-2 GeV.
-
Towards theory constraints on ultralight dark matter from quantum gravity
In asymptotically safe gravity, dimension-five couplings of ultralight scalar dark matter to gauge field strengths vanish and are not generated perturbatively.
-
Nelson-Barr ultralight dark matter
Nelson-Barr mechanism yields ultralight scalar dark matter inducing time-periodic variation in CKM matrix elements, distinguishable from QCD axion and detectable via nuclear clocks.
-
Specially Embedding a Composite Axion Model
Special embedding of the composite axion and QCD gauge groups into a larger product gauge group reduces the domain wall number to unity and induces a controlled bias term from UV instantons that destabilizes the walls.
-
Accidental Peccei-Quinn Symmetry from Chiral Gauge Symmetry and Mirror QCD
A chiral U(1) gauge symmetry generates an accidental Peccei-Quinn symmetry broken by mirror QCD, solving the strong CP problem without a light axion while supplying WIMP dark matter, stochastic gravitational waves, and LHC-testable colored pNGBs.
-
High-Quality Axion Dark Matter at Gravitational Wave Interferometers
In gauged U(1) completions enabling high-quality axion dark matter, cosmic string loops generate a stochastic gravitational wave background with an infrared break frequency that exceeds foregrounds above 10^14 GeV breaking scales and offers a probe at interferometers.
-
Type II Seesaw Leptogenesis in a Majoron background
Spontaneous wash-in leptogenesis in Type II Seesaw with Majoron pNGB background enables baryon asymmetry generation alongside dark matter cogenesis for specific v_T, v_sigma and m_j ranges.
-
Flux Mixing and CP Violation in QCD
Kinetic mixing between hidden-sector fluxes and QCD's topological sector shifts the effective theta angle and produces nonzero <G tilde G>.
-
Looking for Lights from the Darkness: Signals from MeV-scale Solar Axion-like Particles
Solar axion-like particles up to 5.5 MeV produce off-axis MeV photons via two-body decay, enabling new space and terrestrial searches that could probe g_aγ down to 10^{-12} GeV^{-1}.
-
The landscape of QCD axion models
Review classifies QCD axion models extending the standard mass-coupling window and updates bounds from cosmology, astrophysics, and experiments.
- All $2D$ generalised dilaton theories from $d\geq 4$ gravities
- The EDM inverse problem: Identifying the sources of CP violation and PQ breaking with electric dipole moments
- Axion Quality in Warped Extra-Dimension