Failure of Bell's Theorem and the Local Causality of the Entangled Photons

A counterexample to Bell's theorem is presented which uses a pair of photons instead of spin-1/2 particles used in our previous counterexamples. A locally causal protocol is provided for Alice and Bob, which allows them to simulate observing photon polarizations at various angles, and record their results as A=+/-1 in S^3 and B=+/-1 in S^3, respectively. When these results are compared, the correlations are seen to be exactly those predicted by quantum mechanics; namely cos 2(alpha - beta), where alpha and beta are the angles of polarizers. The key ingredient in our counterexample is the topology of 3-sphere, which remains closed under multiplication, thus preserving the locality condition of Bell.Comment: 4 pages; Further elaborations may be found in arXiv:0904.4259, arXiv:quant-ph/0703179, arXiv:0707.1333, arXiv:0806.3078, and arXiv:quant-ph/070324

Whither All the Scope and Generality of Bell's Theorem?

In a recent paper James Owen Weatherall has attempted a simple local-deterministic model for the EPR-Bohm correlation and speculated about why his model fails when my counterexample to Bell's theorem succeeds. Here I bring out the physical, mathematical, and conceptual reasons why his model fails. In particular, I demonstrate why no model based on a tensor representation of the rotation group SU(2) can reproduce the EPR-Bohm correlation. I demonstrate this by calculating the correlation explicitly between measurement results A = +1 or -1 and B = +1 or -1 in a local and deterministic model respecting the spinor representation of SU(2). I conclude by showing how Weatherall's reading of my model is misguided, and bring out a number of misconceptions and unwarranted assumptions in his imitation of my model as it relates to the Bell-CHSH inequalities

Disproof of Bell's Theorem: Further Consolidations

The failure of Bell's theorem for Clifford algebra valued local variables is further consolidated by proving that the conditions of remote parameter independence and remote outcome independence are duly respected within the recently constructed exact, local realistic model for the EPR-Bohm correlations. Since the conjunction of these two conditions is equivalent to the locality condition of Bell, this provides an independent geometric proof of the local causality of the model, at the level of microstates. In addition to local causality, the model respects at least seven other conceptual and operational requirements, arising either from the predictions of quantum mechanics or the premises of Bell's theorem, including the Malus's law for sequential spin measurements. Since the agreement between the predictions of the model and those of quantum mechanics is quantitatively precise in all respects, the ensemble interpretation of the entangled singlet state becomes amenable.Comment: 11 pages; This is a followup to arXiv:quant-ph/0703179; see also arXiv:quant-ph/070324

Why the Quantum Must Yield to Gravity

After providing an extensive overview of the conceptual elements -- such as Einstein's `hole argument' -- that underpin Penrose's proposal for gravitationally induced quantum state reduction, the proposal is constructively criticised. Penrose has suggested a mechanism for objective reduction of quantum states with postulated collapse time T = h/E, where E is an ill-definedness in the gravitational self-energy stemming from the profound conflict between the principles of superposition and general covariance. Here it is argued that, even if Penrose's overall conceptual scheme for the breakdown of quantum mechanics is unreservedly accepted, his formula for the collapse time of superpositions reduces to T --> oo (E --> 0) in the strictly Newtonian regime, which is the domain of his proposed experiment to corroborate the effect. A suggestion is made to rectify this situation. In particular, recognising the cogency of Penrose's reasoning in the domain of full `quantum gravity', it is demonstrated that an appropriate experiment which could in principle corroborate his argued `macroscopic' breakdown of superpositions is not the one involving non-rotating mass distributions as he has suggested, but a Leggett-type SQUID or BEC experiment involving superposed mass distributions in relative rotation. The demonstration thereby brings out one of the distinctive characteristics of Penrose's scheme, rendering it empirically distinguishable from other state reduction theories involving gravity. As an aside, a new geometrical measure of gravity-induced deviation from quantum mechanics in the manner of Penrose is proposed, but now for the canonical commutation relations [Q, P] = ih.Comment: 33 pages (TeX, uses mtexsis) plus 3 figures (epsf). To appear in ``Physics Meets Philosophy at the Planck Scale'' (Cambridge University Press). Two footnotes adde

Bell's Theorem Versus Local Realism in a Quaternionic Model of Physical Space

In the context of EPR-Bohm type experiments and spin detections confined to spacelike hypersurfaces, a local, deterministic and realistic model within a Friedmann-Robertson-Walker spacetime with a constant spatial curvature (S^3 ) is presented that describes simultaneous measurements of the spins of two fermions emerging in a singlet state from the decay of a spinless boson. Exact agreement with the probabilistic predictions of quantum theory is achieved in the model without data rejection, remote contextuality, superdeterminism or backward causation. A singularity-free Clifford-algebraic representation of S^3 with vanishing spatial curvature and non-vanishing torsion is then employed to transform the model in a more elegant form. Several event-by-event numerical simulations of the model are presented, which confirm our analytical results with the accuracy of 4 parts in 10^4 . Possible implications of our results for practical applications such as quantum security protocols and quantum computing are briefly discussed

Disproof of Bell's Theorem

We illustrate an explicit counterexample to Bell's theorem by constructing a pair of spin variables in S^3 that exactly reproduces the EPR-Bohm correlation in a manifestly local-realistic manner.Comment: 1 page; Substantively improved and simplified versio

What Really Sets the Upper Bound on Quantum Correlations?

The discipline of parallelization in the manifold of all possible measurement results is shown to be responsible for the existence of all quantum correlations, with the upper bound on their strength stemming from the maximum of possible torsion within all norm-composing parallelizable manifolds. A profound interplay is thus uncovered between the existence and strength of quantum correlations and the parallelizability of the spheres S^0, S^1, S^3, and S^7 necessitated by the four real division algebras. In particular, parallelization within a unit 3-sphere is shown to be responsible for the existence of EPR and Hardy type correlations, whereas that within a unit 7-sphere is shown to be responsible for the existence of all GHZ type correlations. Moreover, parallelizability in general is shown to be equivalent to the completeness criterion of EPR, in addition to necessitating the locality condition of Bell. It is therefore shown to predetermine both the local outcomes as well as the quantum correlations among the remote outcomes, dictated by the infinite factorizability of points within the spheres S^3 and S^7. The twin illusions of quantum entanglement and non-locality are thus shown to stem from the topologically incomplete accountings of the measurement results.Comment: 23 pages; Forthcoming in a FQXi sponsored book on Bell's Theorem and Quantum Entanglement (2011); Provides foundations to the examples worked out in arXiv:0904.4259, arXiv:quant-ph/0703179, and arXiv:1005.493