50 years ago, John S. Bell introduced in his paper "On the Einstein-Podolski-Rosen paradox" probabilistic inequalities which can be violated by quantum systems. Since then, many more inequalities of this kind -- commonly referred to as Bell or Bell-like inequalities -- have been discovered, and have proved useful in various contexts, from fundamental studies of nature, to applications for secured communication, etc...

These inequalities, however, are spread out in the whole specialized litterature, often under different names (e.g. nonlocal games) and written in their own unique way. This makes it hard to access, compare, or study them. Moreover, little general-purpose information is available about questions related to Bell inequalities.

This website aims at providing a platform to foster exchange on Bell inequalities. It includes a few short texts written by specialists that provide highlights on themes related to Bell inequalities, as well as a compendium of known Bell-like inequalities.

The website relies on a software coded for the occasion, which takes care of the hard work needed to relate Bell inequalities to a single unified inequality format. The algorithms used by this software is described in this paper (in preparation). A version of the software is also available here to use as standalone directly in e.g. Matlab.

This website and all its content is open source, and modifiable by anyone. To contribute to the compendium with an inequality which is not yet incorporated (you can check whether this is the case or not with the function What the facet), follow the instructions provided here (in preparation). It is also easy to add information about the inequalities which are already present in the collection (e.g. an interesting bound, or property of special interest). For this, follow the instructions presented here (in preparation). Finally, new features can be added freely into the main software by accessing the code directly on github.

The parts of the Faacets project are available under the following licenses: