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arXiv · 2504.13251

Light Scalar Fields Foster Production of Primordial Black Holes

Dario L. Lorenzoni·Sarah R. Geller·Zachary Ireland·David I. Kaiser·Evan McDonough·Kyle A. Wittmeier
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Abstract

Scalar fields are ubiquitous in theories of high-energy physics. In the context of cosmic inflation, this suggests the existence of spectator fields, which provide a subdominant source of energy density. We show that spectator fields boost the inflationary production of primordial black holes, with single-field ultra-slow roll evolution supplanted by a phase of evolution along the spectator direction, and primordial perturbations amplified by the resulting multifield dynamics. This generic mechanism is largely free from the severe fine-tuning that afflicts single-field inflationary PBH models.

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Dario L. Lorenzoni, Sarah R. Geller, Zachary Ireland, David I. Kaiser, Evan McDonough, Kyle A. Wittmeier. 2025-04-17. Light Scalar Fields Foster Production of Primordial Black Holes. https://arxiv.org/abs/2504.13251

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