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Scholarly Works (2 results)

  • Thesis
  • Peer Reviewed
UC Irvine Electronic Theses and Dissertations (2023)

In self-interacting dark matter (SIDM) halos undergoing gravothermal evolution, the cores of halos are driven into the short-mean-free-path (SMFP) regime and undergo core collapse. In this dissertation, I study generic SIDM models with velocity-dependent cross-sections and elastic scattering, in SIDM halos experiencing gravothermal collapse. We study the structure and dynamics of halo cores in the SMFP and discover a new approximate universality deep in the SMFP regime. This new SMFP universality allows for the mapping of velocity- dependent cross sections to constant ones in this regime, offering improved predictions for physics occurring in the SMFP evolution of SIDM halos. We devise a semi-analytic recipe to predict the entire SMFP evolution of halos with our newfound SMFP universality by relating this new phase to the long-mean-free-path (LMFP) regime. This methodology streamlines the procedure of acquiring core properties within the SMFP regime and allows for estimates of the minimum mass of the black hole left behind, using simply the initial halo characteristics and particle physics parameters.

    Cover page: Gravothermal Evolution of Generic Self-Interacting Dark Matter ModelsCreative Commons 'BY' version 4.0 license
    • Article
    • Peer Reviewed
    UC Irvine Previously Published Works (2023)
    We study the evolution of isolated self-interacting dark matter halos using spherically symmetric gravothermal equations allowing for the scattering cross-section to be velocity dependent. We focus our attention on the large class of models where the core is in the long mean free path regime for a substantial time. We find that the temporal evolution exhibits an approximate universality that allows velocity-dependent models to be mapped onto velocity-independent models in a well-defined way using the scattering time-scale computed when the halo achieves its minimum central density. We show how this time-scale depends on the halo parameters and an average cross-section computed at the central velocity dispersion when the central density is minimum. The predicted collapse time is fully defined by the scattering time-scale, with negligible variation due to the velocity dependence of the cross-section. We derive new self-similar solutions that provide an analytic understanding of the numerical results.
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