ALMOST CR STRUCTURE ON THE TWISTOR SPACE OF A QUATERNIONIC CR MANIFOLD

摘要

We define an almost CR structure on the twistor space of a quaternionic CR manifold. It is done by choosing a compatible quaternionic pseudohermitian structure, and the proof that the almost CR structure so defined is independent of the choice constitutes the core of this paper. For this, we should suppose that the quaternionic CR structure satisfies a stronger integrability condition, which we newly introduce.