New nilpotent ${cal N}= 2$ superfields

We propose new off-shell models for spontaneously broken local ${cal N}=2$ supersymmetry, in which the supergravity multiplet couples to nilpotent Goldstino superfields that contain either a gauge one-form or a gauge two-form in addition to spin-1/2 Goldstone fermions and auxiliary fields. In the case of ${cal N}=2$ Poincare supersymmetry, we elaborate on the concept of twisted chiral superfields and present a nilpotent ${cal N}=2$ superfield that underlies the cubic nilpotency conditions given in arXiv:1707.03414 in terms of constrained ${cal N}=1$ superfields.