Coherence and Some Quantum Paradoxes

Som Kanjilal, Rafael Wagner, Ernesto F. Galvão

Pre- and post-selection (PPS) paradoxes are striking demonstrations of quantum nonclassicality. Logical PPS paradoxes, where inferences made with the Aharonov-Bergmann-Lebowitz (ABL) rule are exactly 0 or 1, are linked to contextuality. Non-logical paradoxes lack this strong signature. In this work, we analyse more general, non-logical PPS scenarios involving mixed pre- and post-selected states. We show that two such scenarios, the $N$-box and quantum pigeonhole paradoxes, require coherence of both pre- and post-selected states in the basis of the intermediate measurement. This is done by showing each paradox holds if and only if there is weak-value anomaly for a single, paradox-specific operator, together with the fact that weak-value anomaly requires coherence. This clarifies the role of different notions of nonclassicality in these scenarios, highlighting the required quantitative departures from (strictly) classical explanations provided by incoherent sub-theories of quantum theory.

Lili Wang, Zhengli Chen, Wenhua Wang +1 more

Eloy Escagedo Gutierrez

This paper advances The Universal Principle of Collapse (UPC) as a diagnostic method for dissolving paradoxes at inception. By auditing quantum entanglement and nonlocality, it demonstrates that paradoxes do not originate in experiments or mathematics but in language, specifically, in the collapse of metaphor into ontology. Phrases such as “spooky action at a distance” or “instant communication,” even when used ironically, are shown to be linguistic artifacts rather than empirical realities. UPC does not propose new physics or alter quantum formalism. Instead, it reframes paradox as a product of discourse, revealing that paradox ∉ Experiment, paradox ∉ Mathematics, paradox ∈ Language. This recognition dissolves confusion before it coheres, restoring clarity to both scientific and philosophical inquiry. The paper further situates UPC as a bridge between philosophy and quantum mechanics. Language creates coordinate maps of meaning, but when those maps are drawn imprecisely, error propagates across generations of teaching and interpretation. By auditing language against context and intention, UPC collapses error at inception, preventing paradox from becoming legacy. While demonstrated here in the quantum domain, UPC applies wherever metaphor collapses into ontology. In theology, it dissolves paradoxes of faith when metaphor is mistaken for doctrine; in art, it clarifies when symbolism is misread as literal representation; in everyday discourse, it prevents error when figurative speech is taken as fact. Across all domains, UPC functions as a diagnostic principle: paradox dissolves at inception because recognition binds collapse to coherence. Authored by Eloy Escagedo Gutierrez as part of The Universal Principle of Collapse (UPC) Research Project.

José Tito Mendonça, Hugo Terças

Yan‐Han Yang, Xue Yang, Xing-Zhou Zheng +1 more

Quantum coherence plays a crucial role in manipulating and controlling quantum systems, leading to breakthroughs in various fields such as quantum information, quantum sensing, and the detection of gravitational waves. Most coherence witnesses rely on the assumption of being able to control quantum states. Here, we report a device-independent coherence model by extending the standard Bell theory to multiple source scenarios. We propose a Greenberger-Horne-Zeilinger-type paradox to verify the particle and wave behaviors of a coherent carrier. We experimentally generate generalized two-photon entangled states that violate the present paradox, witnessing spatial quantum superposition through local measurements.

Nikolaos Cheimarios, Spyridoula Cheimariou

Logical paradoxes and inconsistent information pose deep challenges in epistemology and the philosophy of logic. Classical systems typically handle contradictions only through external checks or by altering the logical framework, as in Tarski's hierarchy or paraconsistent logics. We propose a novel approach: a quantum circuit architecture that intrinsically enforces logical consistency during its unitary evolution. By encoding self-referential or contradictory propositions into a quantum state, the circuit uses interference effects to suppress inconsistent outcomes while preserving coherent ones. We demonstrate this with the Liar Paradox ("This statement is false"), showing that the quantum model naturally stabilizes truth values that would be paradoxical classically. The framework builds on orthomodular quantum logic treating logical propositions as subspace projectors and connects to belief revision and cognitive modeling by providing a physical mechanism for coherence restoration in epistemic states. This work bridges formal logic and quantum computation, suggesting that consistency can be embedded as a structural property of reasoning systems rather than imposed externally.