西藏阿里地区开展地面原初引力波探测实验的机遇与挑战

The Opportunities and challenges of the primordial gravitational wavesdetection experiment in Ngari Tibet

原初引力波是宇宙暴胀理论的预言之一,直接探测到原初引力波信号是宇宙暴胀理论最强有力的验证,有望揭示宇宙起源之谜。原初引力波至今没有被实验探测到,探测原初引力波最好的方式是精确测量宇宙微波背景辐射(CMB)极化。目前,南极极点和智利阿塔卡马沙漠已有地面CMB极化实验,但北半球仍为空白。已有研究表明,西藏阿里天文台是目前北半球已知的最佳观测CMB的台址。2016年中国科学院启动中美合作"阿里原初引力波探测实验"项目——阿里计划,该项目由中国科学院高能物理研究所牵头,国家天文台、西藏大学等科研机构参与,计划在北半球率先开展地面原初引力波观测实验,可与南半球台址已建成的实验互补和相互印证。阿里原初引力波探测实验一期预计于2020年建成,将是国际上海拔最高的原初引力波观测站,与南极极点、智利阿塔卡马一起为国际原初引力波观测的三大基地。

the primordial gravitational waves （PEWs） is one of the predictions of the theory of cosmic inflation, and the direct detection of the PEWs signal is the most powerful proof of the cosmic inflation theory, which is expected to reveal the mystery of the origin of the universe. The PEW-s has not been experimentally detected yet, and the best way to detect the PEWs is to accurately measure cosmic microwave background radiation （CMB） polarization. At present, ground-based observation of CMB polarization has been carried out at the Antarctic pole and Chilean Atacama desert, but there has been no any observation site in the northern hemisphere. Studies have shown that the Ngari observatory in Tibet is the best known CMB observation site in the northern hemisphere. In 2016, Chinese Academy of Sciences （CAS） launched a China-US cooperation project named ＂Ngari primordial gravitational Wave Detection Experiment＂, i.e. Ngari-CPT plan. This project is leading by CAS, and High Energy Research Institute, National Observatory, Tibet University, and other scientific research institutions are involved. This project attempts to carry out ground-based observation of PEWs in the northern hemisphere, which can be complementary and mutually verified with obsenvations found by those observation sites has ah＇eady been built in the southern hemisphere. With the observatory sites located in Antarctic pole and Chilean Atacama desert, it will become the three major bases of observation of PEWs in the world.