Elliptic quantum group Uq,p((sl2)over-cap) and vertex

Introducing an H-Hopf algebroid structure into U-q,U-p((sl(2)) over cap), we investigate the vertex operators of the elliptic quantum group U-q,U-p((sl(2)) over cap) defined as intertwining operators of infinite dimensional Uq, p((sl(2)) over cap) modules. We show that the vertex operators coincide with the previous results obtained indirectly by using the quasi-Hopf algebra B-q,B-lambda((sl(2)) over cap). This shows a consistency of our H-Hopf algebroid structure even in the case with a nonzero central element.