Radio interferometers, such as the Low-Frequency Array and future Square Kilometre Array, are attempting to measure spherically averaged 21-cm power spectrum from Epoch of Reionization. Understanding dominant physical processes which influence at each length-scale is therefore crucial for interpreting any detection. We study a decomposition quantify evolution its constituent terms set numerical...

Current best limits on the 21 cm signal during reionization are provided at large scales (≳100 Mpc). To model these scales, enormous simulation volumes required, which computationally expensive. We find that primary source of uncertainty is sample variance, determines minimum size simulations required to analyse current and upcoming observations. In large-scale structure simulations, method ‘fi...