On the locality of hidden-variable theories in quantum physics

Claims on the non-existence of hidden-variable theories (resp. local hidden-variable theories) of quantum mechanics are examined. It is shown that Bellʹs locality contains an unnecessarily restrictive condition influenced by a narrow definition of hidden-variable theories, and hence one cannot find any local hidden-variable theory in his framework. A local hidden-variable model is constructed for spin-correlations of two particles against Bellʹs non-existence claim. In this context Merminʹs non-existence claim is analyzed, and a local hidden-variable model for spin-correlations of three particles is constructed against Merminʹs (as well as Greenberger-Horn-Zellingerʹs) non-existence claim.