Time-delay cosmography for ultralight dark matter cores

by Mr Luca Teodori (Weizmann Inst.)

Thursday 28 Nov 2024, 16:00 → 17:30 Asia/Seoul

Room 1423 (KIAS)

Title: Time-delay cosmography for ultralight dark matter cores

Speaker: Mr. Luca Teodori (Weizmann Inst.)

Abstract: If ultralight boson fields exist, then vacuum misalignment populates them with nonzero relic abundance. For a broad range of particle mass the field condenses into fuzzy cores in massive galaxies. We use numerical simulations to test this idea and focusing on ultralight dark matter (ULDM) that makes-up a subdominant fraction of the total dark matter density, consistent with observational constraints. Our simulations mimic galactic halos and explore different initial conditions and levels of sophistication in the modelling of the halo potential. For masses around 1e−25 eV, ULDM cores act as approximate internal mass sheets in strong gravitational lensing, and could first be detected as an H0 bias in cosmography. We discuss prospects, opportunities and caveats of such a scenario.