Modular forms on $${{\,\textrm{SU}\,}}(2,1)$$ with weight $$\frac{1}{3}$$

Abstract

AbstractIn this note, we describe several new examples of holomorphic modular forms on the group $${{\,\textrm{SU}\,}}(2,1)$$ SU ( 2 , 1 ) . These forms are distinguished by having weight $$\frac{1}{3}$$ 1 3 . We also describe a method for determining the levels at which one should expect to find such fractional weight forms.