# Evidence for the epistemic view of quantum states: A toy theory

@article{Spekkens2004EvidenceFT, title={Evidence for the epistemic view of quantum states: A toy theory}, author={Robert W. Spekkens}, journal={Physical Review A}, year={2004}, volume={75}, pages={032110} }

We present a toy theory that is based on a simple principle: the number of questions about the physical state of a system that are answered must always be equal to the number that are unanswered in a state of maximal knowledge. Many quantum phenomena are found to have analogues within this toy theory. These include the noncommutativity of measurements, interference, the multiplicity of convex decompositions of a mixed state, the impossibility of discriminating nonorthogonal states, the…

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