Understand
Can quantum theory be seen as a special case of a more general probabilistic theory, similarly as classical theory is a special case of the quantum one? We study here the class of generalized probabilistic theories defined by the order of interference they exhibit as proposed by Sorkin.
- A simple operational argument shows that the theories require higher-order tensors as a representation of physical states.
- For the third-order interference we derive an explicit theory of "density cubes" and show that quantum theory, i.e.
- theory of density matrices, is naturally embedded in it.
Reading the bibliography…