On the Lei--Bai conjecture on $5$-regular Lin--Lu--Yau Ricci-flat graphs

Guangfu Wang, Wensheng Sun, Yujun Yang

We study the Ricci curvature introduced by Lin, Lu, and Yau. A graph is called Ricci-flat if every edge has curvature zero. Lei and Bai classified $5$-regular symmetric Ricci-flat…