Maximally connected and super arc-connected Bi-Cayley digraphs
  Let X=(V, E) be a digraph. X is maximally connected, if \kappa(X)=\delta(X). X is maximally arc-connected, if \lambda(X)=\delta(X). And X is super arc-connected, if every minimum arc-cut of X is either the set of inarcs of some vertex or the set of outarcs of some vertex. In this paper, we will prove that the strongly connected Bi-Cayley digraphs are maximally connected and maximally arc-connected, and the most of strongly connected Bi-Cayley digraphs are super arc-connected. 
Yuhu Liu, Jixiang Meng
math.CO