



01445nas a2200145   4500008004100000245006100041210005900102260001400161300001400175490000700189520103100196100001701227700001801244856003701262       2009                        eng d00aContextuality and nonlocality in 'no signaling' theories0 aContextuality and nonlocality in no signaling theories  c2009/4/21  a690 - 7110 v393 a  We define a family of 'no signaling' bipartite boxes with arbitrary inputs
and binary outputs, and with a range of marginal probabilities. The defining
correlations are motivated by the Klyachko version of the Kochen-Specker
theorem, so we call these boxes Kochen-Specker-Klyachko boxes or, briefly,
KS-boxes. The marginals cover a variety of cases, from those that can be
simulated classically to the superquantum correlations that saturate the
Clauser-Horne-Shimony-Holt inequality, when the KS-box is a generalized PR-box
(hence a vertex of the `no signaling' polytope). We show that for certain
marginal probabilities a KS-box is classical with respect to nonlocality as
measured by the Clauser-Horne-Shimony-Holt correlation, i.e., no better than
shared randomness as a resource in simulating a PR-box, even though such
KS-boxes cannot be perfectly simulated by classical or quantum resources for
all inputs. We comment on the significance of these results for contextuality
and nonlocality in 'no signaling' theories.
1 aBub, Jeffrey1 aStairs, Allen  uhttp://arxiv.org/abs/0903.1462v2