Pure spinor superfields and Born-Infeld theory

We present a method for introducing and analysing higher-derivative deformations of maximally supersymmetric field theories. Such terms are built in the pure spinor superfield framework, using a set of operators representing physical fields. The action for abelian Born-Infeld theory becomes polynomial in this language, and contains only a four-point interaction in addition to the free action. Simplifications also occur in the non-abelian case.