On an Argument of David Deutsch

We analyse an argument of Deutsch, which purports to show that the deterministic part of classical quantum theory together with deterministic axioms of classical decision theory, together imply that a rational decision maker behaves as if the probabilistic part of quantum theory (Born's law) is true. We uncover two missing assumptions in the argument, and show that the argument also works for an instrumentalist who is prepared to accept that the outcome of a quantum measurement is random in the frequentist sense: Born's law is a consequence of functional and unitary invariance principles belonging to the deterministic part of quantum mechanics. Unfortunately, it turns out that after the necessary corrections we have done no more than give an easier proof of Gleason's theorem under stronger assumptions. However, for some special cases the proof method gives positive results while using different assumptions to Gleason. This leads to the conjecture that the proof could be improved to give the same conclusion as Gleason under unitary invariance together with a much weaker functional invariance condition.Comment: Revision 28-7-03: added reference Final revision 28-05-04. To appear in proceedings of "Quantum Probability and Infinite Dimensional Analysis", Greifswald, 2003; World Scientifi

Teleportation into Quantum Statistics

The paper is a tutorial introduction to quantum information theory, developing the basic model and emphasizing the role of statistics and probability.Comment: Been waiting 3 years for math.S

Better Bell inequalities (passion at a distance)

I explain so-called quantum nonlocality experiments and discuss how to optimize them. Statistical tools from missing data maximum likelihood are crucial. New results are given on CGLMP, CH and ladder inequalities. Open problems are also discussed.Comment: Published at http://dx.doi.org/10.1214/074921707000000328 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

The Three Doors Problem...-s

I argue that we must distinguish between: (0) the Three-Doors-Problem Problem [sic], which is to make sense of some real world question of a real person. (1) a large number of solutions to this meta-problem, i.e., many specific Three-Doors-Problem problems, which are competing mathematizations of the meta-problem (0). Each of the solutions at level (1) can well have a number of different solutions: nice ones and ugly ones; correct ones and incorrect ones. I discuss three level (1) solutions, i.e., three different Monty Hall problems; and try to give three short correct and attractive solutions. These are: an unconditional probability question; a conditional probability question; and a game-theory question. The meta-message of the article is that applied statisticians should beware of solution-driven science.Comment: Submitted to Springer Lexicon of Statistics. Version 2: some minor improvement

The chaotic chameleon

Various local hidden variables models for the singlet correlations exploit the detection loophole, or other loopholes connected with post-selection on coincident arrival times. I consider the connection with a probabilistic simulation technique called rejection-sampling, and pose some natural questions concerning what can be achieved and what cannot be achieved with local (or distributed) rejection sampling. In particular a new and more serious loophole, which we call the coincidence loophole, is introduced.Comment: v.2: 7pp; conjecture 1 disproved by Gisin & Gisin (1999) but which leads to new open problems and conjectures. v.3: minor correction and addition. To appear in proceedings of "Quantum Probability and Infinite Dimensional Analysis", Greifswald, 2003; World Scientific. v.4: major revision in view of solution of another conjecture by Larsson & Gill (2003

No probability loophole in the CHSH

Geurdes (2014, Results in Physics) outlines a probabilistic construction of a counterexample to Bell's theorem. He gives a procedure to repeatedly sample from a specially constructed "pool" of local hidden variable models (depending on a table of numerically calculated parameters) and select from the results one LHV model, determining a random value S of the usual CHSH combination of four (theoretical) correlation values. He claims Prob(|S| > 2) > 0. We expose a fatal flaw in the analysis: the procedure generates a non-local hidden variable model. To disprove this claim, Geurdes should program his procedure and generate random LHV's till he finds one violating the CHSH inequality.Comment: version 3: major revision, new analysis, identification of main erro

Pearle's Hidden-Variable Model Revisited

Pearle (1970) gave an example of a local hidden variables model which exactly reproduced the singlet correlations of quantum theory, through the device of data-rejection: particles can fail to be detected in a way which depends on the hidden variables carried by the particles and on the measurement settings. If the experimenter computes correlations between measurement outcomes of particle pairs for which both particles are detected, he is actually looking at a subsample of particle pairs, determined by interaction involving both measurement settings and the hidden variables carried in the particles. We correct a mistake in Pearle's formulas (a normalization error) and more importantly show that the model is more simple than first appears. We illustrate with visualisations of the model and with a small simulation experiment, with code in the statistical programming language R included in the paper. Open problems are discussed.Comment: 19pp. This is now arXiv version 4 = final revision for journa