Mimicking dark matter in galaxy clusters through a non-minimal   gravitational coupling with matter
  In this work, one shows that a specific non-minimal coupling between the scalar curvature and matter can mimic the dark matter component of galaxy clusters. For this purpose, one assesses the Abell cluster A586, a massive nearby relaxed cluster of galaxies in virial equilibrium, where direct mass estimates and strong-lensing determinations are possible. One then extends the dark matter mimicking to a large sample of galaxy clusters whose density profiles are obtained from the Chandra high quality data, also in virial equilibrium. The total density, which generally follows a cusped profile and reveals a very small baryonic component, can be effectively described within this framework. 
Orfeu Bertolami, Pedro Fraz\~ao, Jorge P\'aramos
gr-qc astro-ph.CO hep-ph