# Exotic probability

**Exotic probability** is a branch of probability theory that deals with probabilities which are outside the normal range of [0, 1].

According to the author of various papers on exotic probability, Saul Youssef, the valid possible alternatives for probability values are the real numbers, the complex numbers and the quaternions.^{[1]} Youssef also cites the work of Richard Feynman, P. A. M. Dirac, Stanley Gudder and S. K. Srinivasan as relevant to exotic probability theories.

Of the application of such theories to quantum mechanics, Bill Jefferys has said: "Such approaches are also not necessary and in my opinion they confuse more than they illuminate."^{[2]}

## See also[edit]

## References[edit]

**^**Youssef, Saul (2001). "Physics with exotic probability theory". arXiv:hep-th/0110253.**^**Jefferys (2002) Newsgroup discussion on sci.physics.research accessed 1-Sept-2010

## External links[edit]

- http://physics.bu.edu/~youssef/quantum/quantum_refs.html
- https://web.archive.org/web/20040327004613/http://fnalpubs.fnal.gov/library/colloq/colloqyoussef.html
- Measuring Negative Probabilities, Demystifying Schroedinger's Cat and Exploring Other Quantum Peculiarities With Trapped Atoms
- MathPages - The Complex Domain of Probability