报告题目：Revealing Dark Matter under the Lens

报 告 人：Dr. Amruth Alfred（香港大学）

报告时间：2024年6月18日（周二）上午10:00

报告地点：物理科学与技术学院老楼C-215

报告摘要：

Unveiling the true nature of Dark Matter (DM), which manifests itself only through gravity, is one of the principal quests in physics. Leading candidates for DM are weakly interacting massive particles (WIMPs) or ultralight bosons (axions), at opposite extremes in mass scales, that have been postulated by competing theories to solve deficiencies in the Standard Model of particle physics. Whereas DM WIMPs behave like discrete particles (ρDM), quantum interference between DM axions is manifested as waves (ψDM). Here, we show (Amruth et al. Nature Astronomy, 2023) that gravitational lensing leaves signatures in multiply-lensed images of background galaxies that reveal whether the foreground lensing galaxy inhabits a ρDM or ψDM halo. The ability of ψDM to resolve lensing anomalies even in demanding cases like HS 0810+2554, together with its success in reproducing other astrophysical observations, tilts the balance towards new physics invoking axions.

报告人简介：

Amruth Alfred, originally from the island of Sri Lanka, is an astrophysicist at the University of Hong Kong and currently holds a Dissertation Year Fellowship which allows for an additional year of research after successfully completing his PhD defense. Amruth is also the recipient of the 2023 Hong Kong Young Scientist Award, which is given annually to the best PhD research in Hong Kong within Physics, Chemistry and Mathematics. His work was featured on the front cover for the June 2023 issue of Nature Astronomy, and has been rated as within the top 1% among all research articles across all journals for how much attention it created.

邀 请 人：廖恺教授