What do you think was before the Big Bang

projective twistor space {\displaystyle \mathbb {PT} } \mathbb{PT} is a three-dimensional complex manifold, complex projective 3-space {\displaystyle \mathbb {CP} ^{3}} \mathbb{CP}^3. Physically it has the interpretation as the space of massless particles with spin. It is the projectivisation of a 4-dimensional complex vector space, non-projective twistor space {\displaystyle \mathbb {T} } \mathbb {T} with a Hermitian form of signature (2,2) and a holomorphic volume form. This can be most naturally understood as the space of chiral (Weyl) spinors for the conformal group {\displaystyle SO(4,2)/\mathbb {Z} _{2}} {\displaystyle SO(4,2)/\mathbb {Z} _{2}} of Minkowski space; it is the fundamental representation of the spin group {\displaystyle SU(2,2)} {\displaystyle SU(2,2)} of the conformal group. This definition can be extended to arbitrary dimensions except that beyond dimension four, one defines projective twistor space to be the space of projective pure spinors for the conformal group.[3][4]