Photon number conservation and the large-scale 21 cm power spectrum in semi-numerical models of reionization

  title={Photon number conservation and the large-scale 21 cm power spectrum in semi-numerical models of reionization},
  author={Tirthankar Roy Choudhury and Aseem Paranjape},
  journal={2019 URSI Asia-Pacific Radio Science Conference (AP-RASC)},
Semi-numerical models of the reionization of neutral hydrogen (HI) based on the excursion set (ES) approach are known to violate photon number conservation at the few per cent level. In this work, we highlight a more severe, previously unrecognized shortcoming of ES models: the large-scale 21 cm power spectrum (equivalently, HI bias $b_{\mathrm{HI}})$is a relatively strong function of the spatial resolution used to generate ES ionization maps. We trace this problem to the fact that photon non… 
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