Spekkens's Symmetric No-Go Theorem

Understand

In a 2008 paper, Spekkens improved the traditional notions of non-negativity of Wigner-style quasi-probability distributions and non-contextuality of observations.

• He showed that the two improved notions are equivalent to each other.
• Then he proved what he called an even-handed no-go theorem.
• The paper contains some minor inaccuracies and one false claim, in the proof of the no-go theorem.