A note on consistent anomalies

Within a BRST formulation, we determine the expressions of the consistent anomaly for superstrings with extended worldsheet supersymmetries of rank N. We consider the O(N) superconformal algebras up to N = 4, as well as the ‘small N = 4’ superalgebra. This is done using a superfield formalism, allowing to recover previous results that were expressed in components. Moreover, we identify the ‘small N = 4’ algebra as the constrained ‘large N = 4’ via a self-duality like condition in superspace.