CGC invited Prof. Yi-Fu Cai from University Of Science And Technology Of China (USTC) to visit Yangzhou University on Nov 10, 2021. Prof. Yi-Fu Cai obtained his Ph.D. from USTC in 2010. He was the postdoc researcher in Arizona State University from Sep 2010 to Aug 2012, and in McGill University from Sep 2012 to May 2015. He came back to join USTC in 2015. In CGC he gave a public lecture named “Exploration of the very early universe and China’s primordial gravitational wave project”.