A non-zero topological angle in a confining dark sector induces CP-violating pion-baryon couplings that naturally generate velocity-dependent dark matter self-interactions and dark electric dipole moments for direct detection.
Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
Models of Cold Dark Matter predict that the distribution of dark matter in galaxy clusters should be cuspy, centrally concentrated. Constant density cores would be strong evidence for beyond-CDM physics, such as Self-Interacting Dark Matter (SIDM). An observable consequence would be oscillations of the Brightest Cluster Galaxy (BCG) in otherwise relaxed galaxy clusters. Offset BCGs have indeed been observed - but only interpreted via a simplified, analytic model of oscillations. We compare these observations to the BAHAMAS-SIDM suite of cosmological simulations, which include SIDM and a fully hydrodynamical treatment of star formation and feedback. We predict that the median offset of BCGs increases with the SIDM cross-section, cluster mass and the amount of stellar mass within 10kpc, while CDM exhibits no trend in mass. Interpolating between the simulated cross-sections, we find that the observations (of 10 clusters) is consistent with CDM at the ~1.5$\sigma$ level, and prefer cross-section $\sigma$/m < 0.12(0.39)cm$^2$/g at 68% (95%) confidence level. This is on the verge of ruling out velocity-independent dark matter self-interactions as the solution to discrepancies between the predicted and observed behaviour of dwarf galaxies, and will be improved by larger surveys by Euclid or SuperBIT.
years
2026 4representative citing papers
MCMC fits of degenerate fermionic dark matter models to eight classical dwarf spheroidal galaxies constrain fermion masses to 100-300 eV and show current data do not strongly favor interacting over non-interacting equations of state.
A minimal electrophilic ALP portal for SIMP pion dark matter widens the allowed parameter space, making an ALP mass of order 10 MeV viable and consistent with the X17 anomaly.
A parameter space analysis of a leptophilic scalar mediator model for Majorana dark matter yields a viable sub-GeV region after applying relic density, cosmological, astrophysical, and laboratory constraints.
citing papers explorer
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Dark Neutrons as Dark Matter: Collisions in Halos and Direct Detection from Dark CP Violation
A non-zero topological angle in a confining dark sector induces CP-violating pion-baryon couplings that naturally generate velocity-dependent dark matter self-interactions and dark electric dipole moments for direct detection.
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Dwarf Galaxy Constraints on Interacting Fermionic Dark Matter
MCMC fits of degenerate fermionic dark matter models to eight classical dwarf spheroidal galaxies constrain fermion masses to 100-300 eV and show current data do not strongly favor interacting over non-interacting equations of state.
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Axion-Like Electrophilic Portal for Pion Dark Matter
A minimal electrophilic ALP portal for SIMP pion dark matter widens the allowed parameter space, making an ALP mass of order 10 MeV viable and consistent with the X17 anomaly.
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Constraints on a Light Leptophilic Scalar from Dark-Sector Couplings
A parameter space analysis of a leptophilic scalar mediator model for Majorana dark matter yields a viable sub-GeV region after applying relic density, cosmological, astrophysical, and laboratory constraints.