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Updated: May 3, 2026

Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Cold dark matter heats up
Andrew Pontzen1, Fabio Governato2
11] Department of Physics and Astronomy, University College London, London WC1E 6BT, UK [2] Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK [3] Balliol College, University of Oxford, Broad Street, Oxford OX1 3BJ, UK.
Abstract:
A principal discovery in modern cosmology is that standard model particles comprise only 5 per cent of the mass-energy budget of the Universe. In the ΛCDM paradigm, the remaining 95 per cent consists of dark energy (Λ) and cold dark matter. ΛCDM is being challenged by its apparent inability to explain the low-density 'cores' of dark matter measured at the centre of galaxies, where centrally concentrated high-density 'cusps' were predicted. But before drawing conclusions, it is necessary to include the effect of gas and stars, historically seen as passive components of galaxies. We now understand that these can inject heat energy into the cold dark matter through a coupling based on rapid gravitational potential fluctuations, explaining the observed low central densities.
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