A manifestly N=2 supersymmetric Born-Infeld action
  A manifestly N=2 supersymmetric completion of the four-dimensional Nambu-Goto-Born-Infeld action, which is self-dual with respect to electric-magnetic duality, is constructed in terms of the abelian N=2 superfield strength W in the conventional N=2 superspace. A relation to the known N=1 supersymmetric Born-Infeld action in N=1 superspace is established. The action found can be considered either as the Goldstone action associated with partial breaking of N=4 supersymmetry down to N=2, with the N=2 vector superfield being a Goldstone field, or, equivalently, as the gauge-fixed superfield action of a D-3-brane in flat six-dimensional ambient spacetime. 
Sergei V. Ketov (ITP, University of Hannover)