Pure de Sitter Supergravity
  Using superconformal methods we derive an explicit de Sitter supergravity
action invariant under spontaneously broken local ${\cal N}=1$ supersymmetry.
The supergravity multiplet interacts with a nilpotent goldstino multiplet. We
present a complete locally supersymmetric action including the graviton and the
fermionic fields, gravitino and goldstino, no scalars. In the global limit when
supergravity multiplet decouples, our action reproduces the Volkov-Akulov
theory. In the unitary gauge where goldstino vanishes we recover pure
supergravity with the positive cosmological constant. The classical equations
of motion, with all fermions vanishing, have a maximally symmetric solution: de
Sitter space.
