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Date
Presenter
Title and Abstract (Slides: authorized only)
2026/04/02
Dr. Mohammad Ali Gorji
Imperfect dark matter with higher derivatives
I introduce a higher-derivative action for dark matter whose energy-momentum tensor describes an imperfect fluid with nonzero pressure, energy flux, and anisotropic stress. On a homogeneous background (e.g. in cosmology), the dynamics coincides with that of pressureless dust, while in the presence of inhomogeneities the higher-derivative terms generate nonzero acceleration and vorticity. This makes it possible to avoid the formation of caustic singularities, even if the strong energy condition is satisfied.
[Based on arXiv:2510.23838 [gr-qc]]