Zahn, OliverMesinger, AndreiMcQuinn, MatthewTrac, HyCen, RenyueHernquist, Lars E.2019-09-202011Zahn, Oliver, Andrei Mesinger, Matthew McQuinn, Hy Trac, Renyue Cen, and Lars E. Hernquist. 2011. “Comparison of Reionization Models: Radiative Transfer Simulations and Approximate, Seminumeric Models.” Monthly Notices of the Royal Astronomical Society 414 (1): 727–38. https://doi.org/10.1111/j.1365-2966.2011.18439.x.0035-87111365-2966http://nrs.harvard.edu/urn-3:HUL.InstRepos:41381781We compare the predictions of four different algorithms for the distribution of ionized gas during the Epoch of Reionization. These algorithms are all used to run a 100 Mpc h(-1) simulation of reionization with the same initial conditions. Two of the algorithms are state-of-the-art ray-tracing radiative transfer codes that use disparate methods to calculate the ionization history. The other two algorithms are fast but more approximate schemes based on iterative applications of a smoothing filter on the underlying source and density fields. We compare these algorithms' resulting ionization and 21-cm fields using several different statistical measures. The two radiative transfer schemes are in excellent agreement judging by the power spectra of both the ionization fields and the 21-cm emission fields ( agreeing to better than 10 per cent) and are in good agreement with the analytic schemes ( better than 50 per cent) over the range of ionized fractions and wavevectors we compare ( 0.2 < <(x)over bar>(i) < 0.7; 0.1 < k < 10 h Mpc(-1)).This agreement suggests that the different approximations involved in the ray-tracing algorithms are sensible and that seminumerical schemes provide a numerically inexpensive, yet fairly accurate, description of the reionization process.en-USJournal Article2019-09-2010.1111/j.1365-2966.2011.18439.x