Abstract:
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The generation of (Bell-)nonlocal correlations, i.e., correlations leading to the violation of a Bell-like inequality,
requires the usage of a nonlocal resource, such as an entangled state. When given a correlation (a collection of
conditional probability distributions) from an experiment or from a theory, it is desirable to determine the extent
to which the participating parties would need to collaborate nonlocally for its (re)production. Here, we propose
to achieve this via the minimal group size (MGS) of the resource, i.e., the smallest number of parties that need
to share a given type of nonlocal resource for the above-mentioned purpose. In addition, we provide a general
recipe—based on the lifting of Bell-like inequalities—to construct MGS witnesses for nonsignaling resources
starting from any given ones. En route to illustrating the applicability of this recipe, we also show that when
restricted to the space of full-correlation functions, nonsignaling resources are as powerful as unconstrained
signaling resources. Explicit examples of c |