AstroParticle Lunch: "Hidden Sector Hydrogen as Dark Matter: Predictions for Small-scale Structure" Anna Kwa (University of California, Irvine)

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November 11, 2016
12:30PM - 1:30PM
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PRB M2005

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Add to Calendar 2016-11-11 12:30:00 2016-11-11 13:30:00 AstroParticle Lunch: "Hidden Sector Hydrogen as Dark Matter: Predictions for Small-scale Structure" Anna Kwa (University of California, Irvine) I will discuss the atomic physics and the astrophysical implications of a model in which the dark matter is the analog of hydrogen in a secluded sector. The self interactions between dark matter particles include both elastic scatterings as well as inelastic processes due to a hyperfine transition. The self-interaction cross sections are computed by numerically solving the coupled Schrodinger equations for this system. The velocity-dependence of the self-interaction cross sections produces the low dark matter density cores seen in spiral galaxies while maintaining consistency with constraints from observations of galaxy clusters. Significant cooling losses may occur due to inelastic excitations to the hyperfine state and subsequent decays (up to about 10% of the collisional heating rate) in this region of parameter space, with implications for the evolution of low mass halos and early growth of black holes. Finally, the minimum halo mass is in the range of 10^3 to 10^7 solar masses for viable regions of parameter space, which is significantly larger than the typical predictions for weakly-interacting dark matter models.    PRB M2005 Center for Cosmology and AstroParticle Physics (CCAPP) ccapp@osu.edu America/New_York public
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I will discuss the atomic physics and the astrophysical implications of a model in which the dark matter is the analog of hydrogen in a secluded sector. The self interactions between dark matter particles include both elastic scatterings as well as inelastic processes due to a hyperfine transition. The self-interaction cross sections are computed by numerically solving the coupled Schrodinger equations for this system. The velocity-dependence of the self-interaction cross sections produces the low dark matter density cores seen in spiral galaxies while maintaining consistency with constraints from observations of galaxy clusters. Significant cooling losses may occur due to inelastic excitations to the hyperfine state and subsequent decays (up to about 10% of the collisional heating rate) in this region of parameter space, with implications for the evolution of low mass halos and early growth of black holes. Finally, the minimum halo mass is in the range of 10^3 to 10^7 solar masses for viable regions of parameter space, which is significantly larger than the typical predictions for weakly-interacting dark matter models.
   

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