Hyperstructures
Hyperstructures are algebraic structures with a multi-valued operation. Hypergroups are the most prevalent in the literature, but there are also hypermonoids , hyperrings , hyperfields, and so on.
For motivation, David Corfield asks on MathOverflow: what are hypergroups and hyperrings good for? Further discussion at the n-Category Cafe .
Literature
TODO: General references
There is also an “analytic” version of a hypergroup: a measurable kernel \(X \times X \to \mathcal{M}(X)\) satisfying the group axioms.
- Dunkl, 1973: The measure algebra of a locally compact hypergroup (doi, pdf)
- Jewett, 1975: Spaces with an abstract convolution of measures (doi)
- Bloom & Herbert, 1995: Harmonic analysis of probability measures on
hypergroups
- Book review in AMS Bulletin
Recent papers on hyperfields (TODO: Connes)