Foundations and Interpretations of Quantum Mechanics

More than a century after its inception, quantum mechanics stands as one of the most empirically successful theories in the history of science. Its predictions have been verified with astonishing precision, and its mathematical framework underpins entire fields of modern physics, chemistry, and technology. Yet despite its practical triumphs, the theory’s underlying meaning—what it truly tells us about the nature of reality—remains a subject of profound and vigorous debate. The Section “Foundations and Interpretations of Quantum Mechanics” in Quantum Reports is dedicated to providing a venue for this critical discourse. We aim to foster a deeper understanding of the theory itself by exploring the conceptual, philosophical, and mathematical questions that lie at its core. 

We invite contributions that critically examine the principles upon which quantum mechanics is built and that propose, refine, or compare the various interpretations developed to make sense of it. From the early Copenhagen interpretation to the more recent developments in quantum information theory, the goal is to move beyond merely applying the rules and to scrutinize the rules themselves. We encourage submissions that address fundamental questions: What is the nature of the wavefunction—is it an ontic element of reality or an epistemic tool summarizing our knowledge? What is the physical mechanism underlying the "collapse" of the wavefunction during a measurement, and is such a collapse fundamental or emergent? How can we reconcile the theory’s inherent nonlocality with the principles of special relativity?

The scope of the section is broad and interdisciplinary, welcoming both physicists and philosophers of science. We are particularly interested in original research articles, comprehensive reviews, and short communications that engage with the following topics: 

• Analyses and Comparisons of Interpretations: Including but not limited to the Copenhagen interpretation, the many-worlds interpretation, Bohmian mechanics, spontaneous wavefunction collapse, relational quantum mechanics, quantum Bayesianism (QBism), and the transactional interpretation.
• The Measurement Problem: Investigations into the transition from quantum superposition to definite outcomes, the role of the observer, and the theory of decoherence.
• Foundational Principles: Examinations of complementarity, uncertainty, nonlocality, contextuality, and the role of probability (Born rule) in quantum theory.
• Quantum Information and Foundational Questions: Exploring the deep connection between information theory and physical reality, including the resource theory of entanglement, the role of the observer in quantum information processing, and the foundations of quantum cryptography and communication.
• Quantum Gravity and Cosmology: Foundational issues arising at the intersection of quantum mechanics and general relativity, such as the problem of time, the nature of quantum spacetime, and the cosmological constant.
• Mathematical and Philosophical Aspects: Rigorous mathematical formulations of foundational problems and the philosophical implications of quantum mechanics for our understanding of causality, realism, and physical reality.

• quantum foundations;
• interpretations of quantum mechanics;
• philosophy of physics;
• quantum theory;
• Hilbert space formalism;
• Copenhagen interpretation;
• many-worlds interpretation (MWI) / Everettian interpretation;
• Bohmian mechanics / de Broglie–Bohm theory / pilot-wave theory;
• collapse models / dynamical reduction models;
• relational quantum mechanics;
• quantum Bayesianism (QBism);
• transactional interpretation;
• modal interpretations;
• consistent histories;
• superdeterminism;
• measurement problem;
• wavefunction collapse / reduction process;
• quantum-to-classical transition;
• decoherence;
• quantum nonlocality / Bell's theorem;
• contextuality;
• Leggett–Garg inequalities;
• macrorealism;
• reality of the wavefunction;
• quantum logic;
• axiomatic quantum mechanics;
• operational approaches;
• quantum information theory;
• entanglement;
• quantum causality;
• indefinite causal order;
• quantum reference frames;
• Wigner's friend paradox;
• quantum metrology (foundational aspects);
• quantum gravity foundations;
• problem of time;
• quantum cosmology;
• emergence of spacetime;
• relativity and quantum mechanics;
• retrocausality;
• time symmetry;
• realism vs. antirealism;
• determinism vs. indeterminism;
• locality;
• counterfactual definiteness;
• epistemology of quantum mechanics.