Projective superspace
In supersymmetry, a theory of particle physics, projective superspace is one way of dealing with 
supersymmetric theories, i.e. with 8 real SUSY generators, in a manifestly covariant manner.
See also
References
- Kuzenko, Sergei (2010). "Lectures on nonlinear sigma-models in projective superspace". Journal of Physics A 43 (44): 56. arXiv:1004.0880. Bibcode:2010JPhA...43R3001K. doi:10.1088/1751-8113/43/44/443001.