An analytic bound on axion parameters in thawing quintessence is derived independently of initial conditions and used with cosmological observations plus quantum gravity constraints to exclude large regions of axion dark energy parameter space.
Cosmology with Ultra-light Pseudo-Nambu-Goldstone Bosons
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
We explore the cosmological implications of an ultra-light pseudo-Nambu-Goldstone boson. With global spontaneous symmetry breaking scale $f \simeq 10^{18}$ GeV and explicit breaking scale comparable to MSW neutrino masses, $M \sim 10^{-3}$ eV, such a field, which acquires a mass $m_\phi \sim M^2/f \sim H_0$, would have become dynamical at recent epochs and currently dominate the energy density of the universe. The field acts as an effective cosmological constant for several expansion times and then relaxes into a condensate of coherent non-relativistic bosons. Such a model can reconcile dynamical estimates of the density parameter, $\Omega_m \sim 0.2$, with a spatially flat universe, and can yield an expansion age $H_0 t_0 \simeq 1$ while remaining consistent with limits from gravitational lens statistics.
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Photon-axion conversion near Kerr black holes produces dimming of photon spectral luminosity that increases with black hole spin, magnetic field strength, and photon-axion coupling, most efficiently at high frequencies.
A mini-review of axion phenomenology showing how light bosons can account for dark matter, drive cosmic acceleration, or contribute to relativistic backgrounds in the early and late Universe.
citing papers explorer
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Bounding axion dark energy
An analytic bound on axion parameters in thawing quintessence is derived independently of initial conditions and used with cosmological observations plus quantum gravity constraints to exclude large regions of axion dark energy parameter space.
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Dimming of Photon Ring due to Photon-Axion Conversion around Kerr Black Holes
Photon-axion conversion near Kerr black holes produces dimming of photon spectral luminosity that increases with black hole spin, magnetic field strength, and photon-axion coupling, most efficiently at high frequencies.
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Axions as Dark Matter, Dark Energy, and Dark Radiation
A mini-review of axion phenomenology showing how light bosons can account for dark matter, drive cosmic acceleration, or contribute to relativistic backgrounds in the early and late Universe.