Some extremal problems on (non-) color critical graphs

Turán-type problem is a fundamental problem in extremal graph theory. The spectral Turán-type problem is a newly developed one in this field. Both of these two types of extremal problems attract more and more researchers’ attention. In this talk, we first introduce the background in this field. Then we present our new results on (non-) color critical graphs along this line. Finally, we propose some further research issues in this field.