In many-particle quantum mechanics the wave function is irreducibly defined on configuration space. In the de Broglie–Bohm theory this fact is made explicit: both the wave function and the actual motion are naturally described as evolving in configuration space, while the familiar three-dimensional motions of particles arise only as projections of this higher-dimensional dynamics. In this paper we argue that configuration space should be regarded as the fundamental arena of quantum dynamics. On this view, the nonlocal correlations observed in ordinary three-dimensional space are not mysterious dynamical influences but direct consequences of local evolution in configuration space. This perspective is developed and illustrated through a detailed analysis of momentum measurement and which-way detection in the iconic two slit experiment, in the two-particle interferometry experiment of Horne–Shimony–Zeilinger and in the Einstein–Podolsky–Rosen experiment.
In many-particle quantum mechanics the wave function is irreducibly defined on configuration space. In the de Broglie–Bohm theory this fact is made explicit: both the wave function and the actual motion are naturally described as evolving in configuration space, while the familiar three-dimensional motions of particles arise only as projections of this higher-dimensional dynamics. In this paper we argue that configuration space should be regarded as the fundamental arena of quantum dynamics. On this view, the nonlocal correlations observed in ordinary three-dimensional space are not mysterious dynamical influences but direct consequences of local evolution in configuration space. This perspective is developed and illustrated through a detailed analysis of momentum measurement and which-way detection in the iconic two slit experiment, in the two-particle interferometry experiment of Horne–Shimony–Zeilinger and in the Einstein–Podolsky–Rosen experiment.
Abstract This paper examines how quantum mechanics, interpreted through the de Broglie–Bohm (deBB) framework, can reveal a deeper underlying reality in configuration space. Rather than proposing new predictions, the aim is to clarify how deBB theory provides a coherent, realist account of massive particle, Hong–Ou–Mandel (HOM)-type correlations—often regarded as uniquely quantum. It is suggested that in this interpretation, configuration space is not simply a mathematical convenience but the fundamental arena in which quantum processes unfold. Observable non local behaviour in space and time arises as a projection of local configuration-space dynamics. The analysis illustrates the explanatory power of the deBB approach and supports the view that the configuration-space wave function carries ontological significance.
I propose a local, realist interpretation of quantum mechanics based on a physical scalar wave field in ordinary three-dimensional space. Each fundamental particle (electron, photon, proton, etc.) possesses its own wave field. The field is fundamental — it is not emitted by the particle, nor does it draw energy from the particle’s motion. The particle is guided by the phase gradient of its own wave via a Bohmian guidance law. The wave evolves according to a linear Klein-Gordon equation. For a single particle this reproduces the full empirical success of quantum mechanics, including the hydrogen spectrum and the double-slit interference pattern. For multiple particles, each particle retains its own local 3D wave; no configuration space is needed. Entanglement is rejected as a fundamental physical phenomenon: the correlations observed in Bell-type experiments are interpreted as ordinary statistical correlations arising from common past interactions, not as evidence of non-locality or of a non-separable quantum state. The quantum mechanical wave function in configuration space is regarded as a mathematical tool, not a physical field. The theory is local, realist, and fully three-dimensional.
This paper provides a detailed and unified historical account of early debates over wave-function realism, the modern term for the view that the wave function of quantum theory is physically real. As this paper will show, the idea of physical waves associated with particles had its roots in work by Einstein and de Broglie, who both originally thought of these waves as propagating in three-dimensional physical space. De Broglie quickly turned this wave--particle duality into an early pilot-wave theory, on which a particle's associated ``phase wave'' piloted or guided the particle along its trajectory. Schrödinger built on de Broglie's phase-wave hypothesis to provide a comprehensive account of the nascent quantum theory. However, Schrödinger's new ``undulatory mechanics'' came at the cost of replacing de Broglie's phase waves propagating in physical space with a wave function propagating in a system's abstract configuration space. The present work will argue that this move from three-dimensional physical space to a many-dimensional configuration space was a decisive reason why the founders of quantum theory uniformly abandoned the physical reality of the wave function. This paper will further clarify that de Broglie introduced two distinct pilot-wave theories, and will then argue that it was Bohm's rediscovery of the second of these two pilot-wave theories over two decades later, as well as Bohm's vociferous defense of wave-function realism, that were responsible for resurrecting the idea of an ontological wave function. Finally, this paper will describe how the influence of Schrödinger and Bohmended up playing a central role in Everett's development of the ``many worlds'' interpretation.
It is argued that in Bohmian mechanics the effective wave function of a subsystem of the universe does not encode the influences of other par-ticles on the subsystem. This suggests that the ontology of Bohmian mechanics does not consist only in Bohmian particles and their posi-tions. It is nonetheless pointed out that since the wave function in configuration space may represent the state of ergodic motion of non-Bohmian particles in three-dimensional space, the ontology of Bohmian mechanics may still consist only in particles. Bohmian mechanics, which is also called the de Broglie-Bohm theory, is a realistic alternative to standard quantum mechanics initially proposed by de Broglie (1928) and later developed by Bohm (1952). According to the theory, a complete realistic description of a quantum system is provided by the configuration defined by the positions of its particles together with its wave function. It has been a hot topic of debate how to interpret the wave function in the theory. Recently Esfeld et al (2013) further developed the nomological interpretation of the wave function, as suggested by Dürr, Goldstein and Zangh̀ı (1997), Goldstein and Teufel (2001) and Goldstein and Zangh̀ı (2012). They argued that the ontology of Bohmian mechanics consists only in Bohmian particles and their positions, and in particular, the effective wave function of a subsystem of the universe encodes the influences of other particles in the universe on the subsystem. In this note, we will argue that this interesting view may be problematic. The Bohmian law of motion is expressed by two equations, a guiding equation for the configuration of particles in three-dimensional space and the Schrödinger equation, describing the time evolution of the wave function, which enters the guiding equation. The law can be formulated as follows: dQ(t) dt = vΨ(t)(Q(t)). (1)
Abstract David Bohm published his “Suggested Interpretation of Quantum Theory in Terms of Hidden Variables” some twenty five years after Louis de Broglie first presented his similar Pilot Wave theory of quantum mechanics. In the following 30 years what became known as the de Broglie–Bohm approach to quantum theory was to a large extent ignored within the physics community. Even David Bohm himself became somewhat disillusioned with the lack of impact of his interpretation of quantum theory and he directed his interest elsewhere. But some 27 years after Bohm had published his interpretation of quantum theory, interest was rekindled in part by new, detailed calculations that demonstrated clearly and graphically, exactly how his interpretation explained quantum phenomena in terms of well defined individual particle trajectories. These computations encompassed two-slit interference, quantum tunnelling, neutron interferometry, Wheeler’s delayed choice experiment, orbital and intrinsic angular momentum, quantum measurement and Einstein–Podolsky–Rosen nonlocal correlations for orbital angular momentum, intrinsic angular momentum and correlated particle interferometry. Since then, the acceptance of the validity of de Broglie–Bohm theory has steadily grown, as has the interest in the consequences of the approach. For my contribution to the current celebratory volume I was asked to provide a personal review specifically of this novel work within its historical context of the last quarter of the twentieth century.