Title： Testing cold dark matter vs. modified gravity with Milky Way's stellar kinematic data
Speaker：Xiaobo Dong, Research Fellow
Unit：Yunnan Astronomical Observatory
Place：Physics Building 407, Haiyun Campus, Xiamen University
Abstract： Using for the first time both the rotation curve data V_rot(R) and the vertical velocity dispersion data sigma(R) of the Milky Way (MW) stars, we test and verify the self-consistency of the quasi-linear formulation of modified newtonian dynamics (QUMOND, Milgrom 2010).
Then, using QUMOND as an effective/practical tool and based purely on the baryonic distribution of the MW, we derive the 3-dimensional distribution of the effective gravitational field (Phi_phantom) of the putative dark matter (DM) halo in the popular DM paradigm. The effective gravitational field Phi_phantom appears not easy to realize with commonly used density profiles of CDM theory.
Lastly we propose expects for mapping the 3-dimensional MW's gravitational field in the LAMOST and GAIA era.