Mirror duality between Calabi-Yau fractional complete intersections

This is an expanded version of the author’s talk at the third annual meeting of International Consortium of Chinese Mathematicians held at USTC in December 2020. In this expository article, we give a survey on joint works with Hosono, Lian, and Yau in arXiv:2003.07148 and arXiv:2008.04039. We also carry out some explicit examples to illustrate our results in enumerative geometry which will appear in our forthcoming papers.