Preprint

PUBDB-2025-05385

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The effects of non Bunch-Davies initial conditions on gravitationally produced relics

Bertuzzo, E. ; Massoni Salla, G. (Corresponding author)DESY* ; Tesi, A.

2026

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Please use a persistent id in citations: doi:10.3204/PUBDB-2025-05385

Report No.: DESY-25-183; arXiv:2603.03430

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.

Note: 13 pages + appendices

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Contributing Institute(s):

1. Theorie-Gruppe (T)

Research Program(s):

1. 611 - Fundamental Particles and Forces (POF4-611) (POF4-611)
2. DFG project G:(GEPRIS)390833306 - EXC 2121: Das Quantisierte Universum II (390833306) (390833306)
3. ASYMMETRY - Essential Asymmetries of Nature (101086085) (101086085)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2026

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