November 6th, 2016, 2:40 pm
It means
1) that that must come from a "quasiprobability distribution" instead of an actual probability distribution because actual probability distribution don't allow probabilities to be negative.
2) in an actual pdf the individual states to which the pdf assigns probabilities are disjoint, uncorrelated, non-negative and sum up to 1. Either Hilary, Donald or Gary wins the election. With quasiprobability the states are coupled.
Probability of winning the election: Hilary 48%, Donald 45%, Gary 7%
Pseudo probability of winning the election: Hilary or Donald 93%, Donald 45%, other -38%
In this Pseudo probability they don't care to correct for the dependencies of states, they don't care that values go negatieve, they just decided they want them to add up to 1, ..or may be not even that! I think in QM they have different pseudo probabilities: don't make the values add up to one, but make the sum of squares add up to one. That means that you're no longer talking about a proper pdf
It should be called "there's a -30% pseudo probability for Hillary winning the general", but people don't care about using clear definitions and helping people understand, they much rather write things that look cool.
I think it's disgusting. Just look at how much time get's wasted here to try and understand that paper. The confusion is deliberate.