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Natural Inflation: Particle Physics Models, Power Law Spectra for Large Scale Structure, and Constraints from COBE

3 Pith papers cite this work. Polarity classification is still indexing.

3 Pith papers citing it
abstract

A pseudo-Nambu-Goldstone boson, with a potential of the form $V(\phi) = \Lambda^4[1 \pm \cos(\phi/f)], naturally gives rise to inflation if $f \sim M_{Pl}$ and $\Lambda \sim M_{GUT}$. We show how this can arise in technicolor-like and superstring models, and work out an explicit string example in the context of multiple gaugino condensation models. We study the cosmology of this model in detail, and find that sufficient reheating to ensure that baryogenesis can take place requires $f > 0.3 M_{Pl}$. The primordial density fluctuation spectrum generated is a non-scale-invariant power law, $P(k) \propto k^{n_s}$, with $n_s \simeq 1 - (M^2_{Pl}/8\pi f^2)$, leading to more power on large length scales than the $n_s = 1$ Harrison-Zeldovich spectrum. The standard CDM model with $0 \la n_s \la 0.6-0.7$ could in principle explain the large-scale clustering observed in the APM and IRAS galaxy surveys as well as large-scale flows, but the COBE microwave anisotropy implies such low amplitudes (or high bias factors, $b>2$) for these CDM models that galaxy formation occurs too late to be viable; combining COBE with sufficiently early galaxy formation or the large-scale flows leads to $n_s >0.6$, or $f > 0.3 M_{Pl}$ as well. For extended and power law inflation models, this constraint is even tighter, $n_s > 0.7$; combined with other bounds on large bubbles in extended inflation, this leaves little room for most extended models.

citation-role summary

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citation-polarity summary

years

2026 2 2025 1

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UNVERDICTED 3

roles

background 3

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background 3

representative citing papers

Bounding axion dark energy

astro-ph.CO · 2026-04-10 · unverdicted · novelty 6.0

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.

Axions as Dark Matter, Dark Energy, and Dark Radiation

hep-ph · 2025-09-21 · unverdicted · novelty 2.0

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

Showing 3 of 3 citing papers.

  • Bounding axion dark energy astro-ph.CO · 2026-04-10 · unverdicted · none · ref 43

    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.

  • Primordial Magnetogenesis and Gravitational Waves from ALP-assisted Phase Transition hep-ph · 2026-04-22 · unverdicted · none · ref 89

    ALP-assisted first-order phase transitions can explain observed intergalactic magnetic fields and produce detectable gravitational waves, linking cosmology with particle physics searches.

  • Axions as Dark Matter, Dark Energy, and Dark Radiation hep-ph · 2025-09-21 · unverdicted · none · ref 43 · internal anchor

    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.