Homogeneous quandles with commutative inner automorphism groups

In this paper, we give a characterization for homogeneous quandles with commutative inner automorphism groups. In particular, it is shown that such a quandle is expressed as an abelian extension of a trivial quandle. Our construction is a generalization of the recent work by Furuki and Tamaru, which gives the construction of disconnected flat quandles.