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碩博班專題討論(Colloquium)

(取消!)(CANCELLED!) Testing the Collisionless Nature of Dark Matter in Galaxy Clusters using Gravitational Lensing

演講者 : Keiichi Umetsu 梅津敬一 Research Fellow (Academia Sinica Institute of Astronomy and Astrophysics)
演講時間 : 2022 / 12 / 09 14:10
理學教學新大樓物理系1F 36102教室
理學教學新大樓物理系1F 36102教室 位於....
Galaxy clusters are observed to be the most massive cosmic objects
bound by gravity. The deep potential well of galaxy clusters indicates
that their mass is dominated by electromagnetically invisible dark
matter, which is found to make up about 85% of the total matter in the
Universe. Gravitational lensing predicted by Einstein’s theory of
general relativity offers a powerful way to unlock the mysterious
nature of dark matter. In this talk, we will discuss prospects for
studying the dark matter structure in galaxy clusters and constraining
the nature of dark matter from combined strong and weak gravitational
lensing. In particular, we will discuss the possibility of using the
radial acceleration relation (RAR) in galaxy clusters to constrain the
self-interacting dark matter cross section. By comparing the
theoretical predictions derived from cosmological hydrodynamical
simulations with the RAR inferred from CLASH lensing and X-ray
observations, we will demonstrate the power of the cluster-scale RAR
for testing the collisionless nature of dark matter (Tam, Umetsu,
Robertson, & McCarthy 2022).