Jitendra Prakash, Department of Pure Mathematics, University of Waterloo
"Non-closure of the set of quantum correlations"
Consider a bipartite system with two observers, Alice and Bob, who are performing measurements in their labs. One model for quantum mechanics says that if H and K are finite-dimensional Hilbert spaces associated to Alice's and Bob's labs, respectively, then the joint lab is described by the tensor product of H and K. However in the commuting quantum model, it is assumed that there is a single Hilbert space (possibly infinite-dimensional) describing the joint lab, and the measurement operators corresponding to Alice's measurements commute with those of Bob's. Tsirelson's original question asked whether these two models were essentially the same. We shall show that these two models are different for bipartite systems with five quantum experiments and binary outcomes for each experiment, by using the notion of correlation functions of graphs.
This is a joint work with Ken Dykema and Vern Paulsen.
MC 5417