-optimally connected mixed Cayley graphs

A restricted edge cut of a graph X is an edge set whose removal disconnects X into non-trivial components. The cardinality of the minimum restricted edge cut is the restricted edge connectivity, denoted by λ ′ ( X ) . If X has restricted edge cuts and λ ′ ( X ) achieves the upper bound of the restricted edge connectivity, X is said to be λ ′ -optimal. In this work, we will prove that for all but a few exceptions, the mixed Cayley graph is λ ′ -optimal.