Research

 

Indirect dark matter searches

Dark matter can decay, annihilate or oscillate into Standard Model particles, leading to characteristic spatial and spectral anomalies in the astrophysical sky. My work combines particle dark matter models with astrophysical modeling to derive constraints on dark matter scenarios from keV to PeV energies. In the X-ray and MeV bands, we analyzed eROSITA forecasts Dekker et al. (2021) and INTEGRAL/SPI data Calore et al. (2023) to set leading limits on light and decaying dark matter candidates. Neutrinos provide a unique complementary probe for heavy dark matter, and we set stringent limits on various dark matter models and by applying angular power spectrum and Monte Carlo methods in Dekker et al. (2020) and Basegmez du Pree et al. (2021), and likelihood analysis with future mock KM3NeT data Ng et al. (2020). Moreover, multi-messenger observations of Active Galactic Nuclei are promising targets for axion-like particles, as we showed in Dekker et al. (2025).

 
 
 
 

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Cosmic small-scale probes

Microscopic properties of dark matter shape the formation of structure on small scales, leaving observational imprints on dwarf galaxies - systems that are strongly dark matter dominated. I co-developed the public sashimi tool for Semi-Analytical SubHalo Inference Modeling (available here), which predicts subhalo populations in different cosmologies. In Dekker et al. (2022) and Tan et al. (2025) we set stringent constraints on warm dark matter, and mixed cold-warm dark matter. These limits can be translated to a broad class of dark matter candidates using the framework we present in D’Eramo et al. (2025). Moreover, the central densities of dwarf galaxies trace their formation time, and provide a unique probe of the small-scale matter power spectrum (k ~ 10-100 / Mpc), as shown in Dekker et al. (2025)

 
 
 
 
 
 
 

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High energy neutrinos

Astrophysical neutrinos with Tev and PeV energies have been detected with IceCube in the last decade. Neutrinos travel in an unattenuated and undeviated path towards Earth and can therefore provide insight into acceleration processes, on the origin of high-energy cosmic rays and on the potential discovery of new distant sources. The origin of the observed neutrino flux is however unknown. In Dekker et al. (2019) we constrain the contribution of astrophysical source populations to the observed neutrino sky by considering isotropic and anisotropic components of the diffuse neutrino data. With current data, rare and bright source classes can be constrained.

 
 
 
 

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