  We propose a definition of irregular vertex operators in the H3+ WZW model.
Our definition is compatible with the duality [1] between the H3+ WZW model and
Liouville theory, and we provide the explicit map between correlation functions
of irregular vertex operators in the two conformal field theories. Our
definition of irregular vertex operators is motivated by relations to partition
functions of N=2 gauge theory and scattering amplitudes in N=4 gauge theory
