Trung tâm Vệ tinh Quốc gia trân trọng kính mời thầy/cô/anh/chị/em tới tham dự seminar với thông tin chi tiết như sau:
- Chủ đề: Cosmology from Gravitational Lens Time Delays; tạm dịch: Nghiên cứu Vũ trụ học từ hiệu ứng trễ thời gian thấu kính hấp dẫn
- Người trình bày: TS. Kenneth Wong, Đài Thiên văn Quốc gia Nhật Bản (NAOJ)
- Ngôn ngữ: Tiếng Anh
- Thời gian: 9h00, thứ Năm, ngày 4/5/2017
- Địa điểm: Phòng họp 803, Tòa nhà VNSC (A6)
Cosmology from Gravitational Lens Time Delays
Strong gravitational lens systems with time delays between the multiple images are a powerful probe of cosmology and astrophysics. In particular, the time-delay distance from such a system is primarily sensitive to the Hubble constant (H0) that is key to probing dark energy, neutrino physics, and the spatial curvature of the Universe, as well as discovering new physics. The H0 Lenses In COSMOGRAIL’s Wellspring (H0LiCOW) project aims to measure H0 to <3.5% precision from five lensed quasars using deep Hubble Space Telescope imaging, precise time delay measurements from the COSMOGRAIL monitoring project, a measurement of the velocity dispersion of the lens galaxies, and a characterization of the mass distribution along the line of sight. The most recent H0LiCOW analysis of the system HE 0435-1223 is able to constrain the time-delay distance to a precision of ~8%. In combination with the previous two H0LiCOW lenses, we constrain H0 to ~3.8% precision for a flat Lambda CDM cosmology. These results are consistent with independent determinations of H0 using the distance ladder method and are in moderate tension with the latest Planck results for a similar cosmology, hinting at possible new physics beyond the standard LCDM model and highlighting the importance of this independent probe.