Non-injective maps occur in coarse-grained descriptions, but their relation to Bell non-factorisability requires a separate compatibility theorem. We prove that non-injectivity alone has no Bell-discriminating power. Any Bell-local model can be made arbitrarily non-injective by adjoining erased independent labels, without changing any observable probability or Bell functional. More strongly, every finite empirical model, Bell-local or not, admits a setting-independent non-injective pushforward realisation. Fibre multiplicity and information discarded inside fibres therefore cannot by themselves bound the CHSH value. We give an explicit Bell-local model whose four observable maps have fibres of size eight, and show that output Shannon entropy does not measure non-injectivity. We also isolate the correct obstruction in the binary CHSH scenario: the PR parity family has compatible one-site marginals but no setting-independent global coupling over \((A_0,A_1,B_0,B_1)\). The obstruction is cross-context incompatibility, not many-to-one behaviour within any individual context. Interpretive status: non-injective projection may remain part of an effective architecture, but it cannot explain Bell violation unless an additional global-coupling obstruction is supplied or derived.
Non-injective maps occur in coarse-grained descriptions, but their relation to Bell non-factorisability requires a separate compatibility theorem. We prove that non-injectivity alone has no Bell-discriminating power. Any Bell-local model can be made arbitrarily non-injective by adjoining erased independent labels, without changing any observable probability or Bell functional. More strongly, every finite empirical model, Bell-local or not, admits a setting-independent non-injective pushforward realisation. Fibre multiplicity and information discarded inside fibres therefore cannot by themselves bound the CHSH value. We give an explicit Bell-local model whose four observable maps have fibres of size eight, and show that output Shannon entropy does not measure non-injectivity. We also isolate the correct obstruction in the binary CHSH scenario: the PR parity family has compatible one-site marginals but no setting-independent global coupling over ((A_0,A_1,B_0,B_1)). The obstruction is cross-context incompatibility, not many-to-one behaviour within any individual context. Interpretive status: non-injective projection may remain part of an effective architecture, but it cannot explain Bell violation unless an additional global-coupling obstruction is supplied or derived.
Violations of Bell inequalities are commonly interpreted as evidence for either nonlocal dynamics or the failure of classical realism. In this work, we show that Bell-type correlations can arise without invoking superluminal influences, retrocausality, or local hidden variables, provided that the mapping between underlying configurations and observable outcomes is non-injective. We study a class of effective models in which multiple underlying states correspond to the same observable description. Such non-injective projections generically induce non-factorizable joint probability structures at the level of observables, even when the underlying description itself is fully local and deterministic. As a result, the statistical assumptions required to derive Bell inequalities are violated at the effective level, while locality is preserved at the underlying level. Within this framework, quantum correlations emerge as structural features of projected descriptions rather than as signatures of nonlocal causation. We clarify the precise assumption of Bell’s theorem that fails in this setting and show how classical behavior is recovered in regimes where the effective projection becomes approximately injective, suppressing nonlocal correlations through decoherence and environmental coarse-graining. Our results suggest that Bell inequality violations need not reflect a fundamental nonlocality of nature, but may instead indicate intrinsic information loss induced by non-injective mappings between underlying configurations and observable descriptions.
Violations of Bell inequalities are commonly interpreted as evidence for nonlocal influences or as constraints on realist descriptions. We show that the failure of Bell-type factorizability arises naturally when observable outcomes are obtained through a non-injective mapping from an underlying configuration space. In this setting, the standard factorization assumption can be viewed as an implicit requirement that observable variables admit a jointly factorizable completion at the underlying level. We demonstrate that this requirement need not hold when the mapping from underlying configurations to observables is many-to-one. The resulting breakdown of probabilistic factorization does not rely on superluminal dynamics or hidden causal influences, but follows from information loss under projection. Observable outcomes correspond to equivalence classes of underlying configurations, preventing the assignment of independent local variables. We illustrate this mechanism with an explicit toy model producing Bell–CHSH violations while preserving operational no-signalling and statistical independence of measurement settings. The model is not intended to reproduce quantum correlations quantitatively, and may exceed the Tsirelson bound; its role is to isolate the structural origin of the violation. This analysis does not contradict Bell’s theorem, but identifies a class of effective descriptions for which its factorizability assumption does not apply. The framework preserves locality at the underlying level, introduces no additional hidden-variable dynamics, and does not modify quantum mechanics. It clarifies how classical factorization is recovered in regimes where the effective mapping becomes approximately injective. In the operator language of quantum theory, the same mechanism admits a natural reformulation in terms of reduction to an effective observable subalgebra by a noncommutative conditional expectation.
We derive the Bell–CHSH inequality as a conditional theorem inside Charlton Geometry (CG), rather than as an independent axiom about “local realism”. The key CG primitive is non-invertibility, η(ω) = η(−ω), which forces an observational quotient and produces irrecoverable “lost state” carried by polarity and intrinsic phase. In a bipartite experiment, Bell’s bound is recovered exactly when one adds an additional factorization condition asserting that outcomes depend only on local settings and a local lift choice, i.e. that the lost-state fiber decomposes into independent local fibers. Within CG, the natural geometric coupling of two regions through shared lift and holonomy generically violates that factorization while preserving operational no-signaling, so the Bell inequality becomes a theorem about a restricted subclass of quotients rather than a universal constraint. Using the Born brick as an upstream theorem that fixes the unique binary law cos2(θ/2) on the spin-lifted setting space, we recover the standard singlet correlation E(a, b) = −a °§ b and the Tsirelson bound 2√2 as the sharp CG-compatible CHSH maximum. In this framing, Bell violation is not an ontic miracle but the expected signature of a globally shared, non-invertible geometric substate whose reversal cannot be represented
Bell's theorem is popularly stated as the inconsistency of quantum theory with local realism. Realism is here formalized by the ontological models framework, where elements of reality are points of a measurable space and probabilities obey the Kolmogorov axioms. In the Bell scenario, locally causal ontological models posit a common cause supporting a global valuation, a joint assignment of outcomes to all measurements at once, across incompatible contexts. Within this notion of realism, Bell's theorem makes any realist explanation of the quantum predictions conspiratorial: any mechanism, whether superluminal, superdeterministic, or retrocausal, must be finely tuned so as never to manifest operationally. We redefine realism through a new ontological framework that generalizes the standard one. The elements of reality, which we call records, are no longer points but relational parts of a point-free generalization of a topological space (sublocales of a locale). A record shared by two incompatible contexts establishes the sameness of a measurement across them, without such pairwise identities composing into a global valuation, and the common cause is then a web of such records. Within this framework, Bell's no-go theorem becomes a go theorem: local causality, restated for records, is no longer at odds with the quantum statistics. This is possible because modularity, the inclusion-exclusion law of classical probability, fails across incompatible contexts, so that the probability theory generalizes Kolmogorov's. We exhibit explicit models reproducing several quantum strategies, including the optimal CHSH violation. More broadly, locally causal models of this kind attain every Bell-CHSH value up to the algebraic maximum. A realist explanation of the quantum predictions need not be conspiratorial; every causal influence posited by these models is reflected in the operational predictions.
Bell nonlocality is the experimentally testable incompatibility between quantum correlations and explanations based on local hidden variables. Its significance now extends beyond the foundations of quantum mechanics: a Bell-inequality violation can certify entanglement, randomness, measurement incompatibility, and cryptographic security without requiring a detailed model of the devices producing the observed data. This article develops the mathematical structure of Bell experiments and explains its role in device-independent quantum information. Conditional probability distributions are classified into local, quantum, and no-signalling sets; the Clauser-Horne-Shimony-Holt inequality is derived, and its classical, quantum, and algebraic limits are distinguished. Tsirelson’s bound is obtained from the CHSH operator, while Popescu-Rohrlich correlations demonstrate that no-signalling alone does not identify the quantum set. The relation between entanglement and nonlocality is examined through local entangled states, hidden nonlocality, and activation. Nonlocal games, semidefinite relaxations, self-testing, certified randomness, and device-independent quantum key distribution are treated as operational consequences of Bell violation. Particular attention is given to entropy accumulation, finite-data security, loophole-free experiments, and the limitations of device independence. Bell nonlocality emerges as both a foundational separation between classical and quantum causal models and a quantitative resource for cryptographic and informational tasks.
We derive the Bell–CHSH inequality as a conditional theorem inside Charlton Geometry (CG), rather than as an independent axiom about “local realism”. The key CG primitive is non-invertibility, η(ω) = η(−ω), which forces an observational quotient and produces irrecoverable “lost state” carried by polarity and intrinsic phase. In a bipartite experiment, Bell’s bound is recovered exactly when one adds an additional factorization condition asserting that outcomes depend only on local settings and a local lift choice, i.e. that the lost-state fiber decomposes into independent local fibers. Within CG, the natural geometric coupling of two regions through shared lift and holonomy generically violates that factorization while preserving operational no-signaling, so the Bell inequality becomes a theorem about a restricted subclass of quotients rather than a universal constraint. Using the Born brick as an upstream theorem that fixes the unique binary law cos2(θ/2) on the spin-lifted setting space, we recover the standard singlet correlation E(a, b) = −a °§ b and the Tsirelson bound 2√2 as the sharp CG-compatible CHSH maximum. In this framing, Bell violation is not an ontic miracle but the expected signature of a globally shared, non-invertible geometric substate whose reversal cannot be represented Original DOI: 10.5281/zenodo.18216032 Version: 0.9.0