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Exploring the freeze-in mechanism for scotogenic singlet dark matter
by Ugo de Noyers, Björn Herrmann
Submission summary
| Authors (as registered SciPost users): | Björn Herrmann |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2512.13563v1 (pdf) |
| Date submitted: | Dec. 19, 2025, 10:50 a.m. |
| Submitted by: | Björn Herrmann |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Phenomenological |
Abstract
We present an exploratory study of the freeze-in mechanism within a scotogenic framework, where dark matter can either be a scalar singlet or a fermion singlet. Based on a random parameter scan, we show that large portions of the parameter space feature a dark matter relic density in agreement with the limits derived by Planck. Moreover, constraints related to lepton flavour violation are mostly respected within such parameter regions. Our study shows that it will be worth to further investigate the freeze-in mechanism within scotogenic frameworks.
Author indications on fulfilling journal expectations
- Provide a novel and synergetic link between different research areas.
- Open a new pathway in an existing or a new research direction, with clear potential for multi-pronged follow-up work
- Detail a groundbreaking theoretical/experimental/computational discovery
- Present a breakthrough on a previously-identified and long-standing research stumbling block
Current status:
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Report
The present manuscript investigates freeze-in production of singlet fermionic or scalar dark matter (DM) within the well-established scotogenic model. The paper is generally well written, and the analysis appears sufficiently sound for publication in SciPost. However, before recommending it, I have a few comments and questions that the authors needs to address:
1) The model framework includes a massive charged scalar. How existing experimental constraints from charged scalar searches restrict the allowed DM parameter space (if at all)?
2) It would be useful to include the Feynman diagrams for the processes contributing to the DM relic abundance. Even if not all processes are shown, at least the dominant ones should be presented. Without this, it is somewhat difficult to understand why and how the geometric mean of the couplings enters the final result.
3) How do the authors ensure that the out of equilibrium condition required for freeze-in production is satisfied throughout the relevant cosmological history? This point should be clearly stated in the manuscript, preferably with an order of magnitude estimate of the relevant coupling strengths.
4) How robust is the correlation among couplings that simultaneously yields the correct DM abundance while satisfying constraints from LFV observables? In particular, do the same couplings always control both sectors, or can they be partially decoupled? This should be explicitly discussed.
5) Why is it not possible to have both the fermion and the scalar simultaneously as DM (a 2-component scenario)?
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