Speaker
Description
We propose a novel mechanism for constraining warm dark matter (WDM) models via the so-called “memory of reionization” effect, which is that gas in the intergalactic medium (IGM) after cosmic reionization can be affected significantly by inhomogeneous reionization of hydrogen. The suppression of small-scale structure due to WDM affects the evolution of post-reionization IGM, while thermal relics can couple to ionized bubbles at the scales of tens of Mpc. As such, the small-scale effect due to WDM can leave an imprint on the gas at large scales, which can be observed by Ly$\alpha$ forest. We forecast the accuracy of constraints on WDM using Ly$\alpha$ forest 3D power spectrum with DESI-like surveys, and demonstrate that this approach can provide an unprecedentedly tight constraint on WDM mass.
