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arXiv · 2603.03430

The effects of non Bunch-Davies initial conditions on gravitationally produced relics

Enrico Bertuzzo·Gabriel M. Salla·Andrea Tesi
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Abstract

Typical gravitational production of relics from amplification of inflationary perturbations assumes Bunch-Davies initial conditions, i.e. a vacuum with initially no particles. In this paper we investigate the impact of non Bunch-Davies initial conditions to the final abundance of relics, with particular attention to the parameter space where the total dark matter abundance is reproduced. We present a general framework for any initial condition, through which we show their non-trivial effect on both spectrum and late-time abundance. We argue that for particles whose source of conformal symmetry breaking comes only from a mass term (spin-1/2 fermions and conformally coupled scalars), the choice of initial conditions has little impact on the mass range relevant to dark matter. For other particles, e.g. the longitudinal mode of spin-1, we see a large deviation from the standard computation. We exemplify and quantify our results with an initial thermal state and a two-stage inflation scenario, highlighting that the total dark matter can be obtained for a wide range of masses.

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Enrico Bertuzzo, Gabriel M. Salla, Andrea Tesi. 2026-03-03. The effects of non Bunch-Davies initial conditions on gravitationally produced relics. https://arxiv.org/abs/2603.03430

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