The "Chaotic Ball" model,local realism and the Bell test loopholes

TL;DR

This paper presents a simple model demonstrating that common assumptions about closing the detection loophole in Bell tests may be unjustified, suggesting that experimental violations of Bell inequalities do not conclusively refute local realism.

Contribution

The paper introduces a model showing that the detection loophole can bias Bell test results, challenging the assumption that current experiments definitively refute local realism.

Findings

Detection loophole can bias Bell test outcomes

Bell test violations may be explained by local realist models

Experimental evidence refutes only a narrow class of local hidden variable theories

Abstract

It has long been known that the "detection loophole", present when detector efficiencies are below a critical figure, could open the way for alternative "local realist" explanations for the violation of Bell tests. It has in recent years become common to assume the loophole can be ignored, regardless of which version of the Bell test is employed. A simple model is presented that illustrates that this may not be justified. Two of the versions -- the standard test of form -2 <= S <= 2 and the currently-popular "visibility" test -- are at grave risk of bias. Statements implying that experimental evidence "refutes local realism" or shows that the quantum world really is "weird" should be reviewed. The detection loophole is on its own unlikely to account for more than one or two test violations, but when taken in conjunction with other loopholes (briefly discussed) it is seen that the experiments refute only a narrow class of "local hidden variable" models, applicable to idealised situations, not to the real world. The full class of local realist models provides straightforward explanations not only for the publicised Bell-test violations but also for some lesser-known "anomalies".