06/15 2022 Seminar
  • Title题目 Constraining ultralight bosonic dark matter with Keck observations of S2’s orbit and kinematics
  • Speaker报告人 袁官文 (PMO/USTC)
  • Date日期 2022年6月15日 15:00
  • Venue地点 腾讯会议链接 https://meeting.tencent.com/dm/1JhjCdqowlyu
  • Abstract摘要
    Ultralight scalar dark matter is expected to be able to form a cloud surrounding the supermassive black hole (SMBH) in the Galactic center. With increasing precision of the observations of the stellar kinematics around the SMBH, tiny effects from such a dark matter cloud, including its gravitational perturbation and the direct coupling with ordinary matter may be detectable. In this work, we search for possible evidence of the scalar cloud using accurate orbital measurements of the S2 star around Sgr A*. We solve the first order Post-Newtonian equation, considering simultaneously the extended mass distribution of the scalar cloud and the frequency shift induced by the additional coupling via Higgs-portal or photon-portal interaction. We find that the astrometric and spectroscopic data of the S2 star are well consistent with the scenario of point-like mass of Sgr A*. We thus derive upper limits of the extended mass and the coupling of the new interaction. The limits of the Higgs coupling and extended mass of the scalar cloud are the most stringent ones for the scalar mass window between 3.2×1e-19eV and 1.6×1e-18eV.
    (Based on arXiv: 2205.04970)