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arXiv · 2510.05967

Stochastic Gravitational Waves from Modulated Reheating

Michele Benaco·Dimitrios Karamitros·Sami Nurmi·Kimmo Tuominen
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Abstract

We investigate scalar-induced stochastic gravitational waves from adiabatic curvature perturbations sourced by a spectator field via the modulated reheating mechanism. We consider a spectator scalar with Higgs-like couplings and inflaton decay via shift symmetric dimension-five operators. The spectator is assumed to be in the Sitter vacuum and it sources blue-tilted, strongly non-Gaussian curvature perturbations which can dominate the spectrum on small scales $k \gg \rm{Mpc}^{-1}$. We find that the setup could generate a gravitational wave signal testable by surveys like BBO and DECIGO but only for large coupling values not expected in low-energy particle physics setups that can be perturbatively extrapolated up to the inflationary scale.

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Michele Benaco, Dimitrios Karamitros, Sami Nurmi, Kimmo Tuominen. 2025-10-07. Stochastic Gravitational Waves from Modulated Reheating. https://doi.org/10.1088/1475-7516%2F2026%2F04%2F046

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