Alex Ji @alexji.bsky.social · 03/09/2026Anna Nierenberg: strong lensing images affected by low mass halos in the lens, either deflection or magnification. Can do resolved source, single extreme subhalo detection; and resolved/unresolved source with multiple subhalos #KICPDM 100 0
Alex Ji @alexji.bsky.social · 03/09/2026Nierenberg: The single subhalo detections so far all seem to be very concentrated (e.g. arxiv.org/abs/2601.02466 most recently). #KICPDMarxiv.orgA possible challenge for Cold and Warm Dark MatterMeasuring the density profile and mass concentration of dark-matter haloes is a key test of the standard cold dark matter paradigm. Such objects are dark and thus challenging to characterise, but they... 100 0
Alex Ji @alexji.bsky.social · 03/09/2026Nierenberg: If the source is not resolved (e.g. quasars), it causes magnification (at the observed image resolution). Multiple images can give flux ratios, forward model realizations of all the subhalos in foreground. With JWST, constrain m_wdm > 10 keV, M_halo_min < 10^8 Msun #KICPDM 100 0
