The author's attempt to construct a local causal model of quantum theory (QT) that includes quantum field theory (QFT) resulted in the identification of "quantum objects" as the elementary units of causality and locality. Quantum objects are collections of particles (including single particles) whose collective dynamics and measurement results can only be described by the laws of QT and QFT. Local causal models of quantum objects' internal dynamics are not possible if a locality is understood as a space-point locality. Within quantum objects, state transitions may occur which instantly affect the whole quantum object. The identification of quantum objects as the elementary units of causality and locality has two primary implications for a causal model of quantum objects: (1) quantum objects run autonomously with system-state update frequencies based on their local proper times and with either no or minimal dependency on external parameters. (2) The laws of physics that describe global (but relativistic) interrelationships must be translated to a causal model of interactions between quantum objects and interactions between quantum objects and the space.
The author's attempt to construct a local causal model of quantum theory (QT) that includes quantum field theory (QFT) resulted in the identification of "quantum objects" as the elementary units of causality and locality. Quantum objects are collections of particles (including single particles) whose collective dynamics and measurement results can only be described by the laws of QT and QFT. Local causal models of quantum objects' internal dynamics are not possible if a locality is understood as a space-point locality. Within quantum objects, state transitions may occur which instantly affect the whole quantum object. The identification of quantum objects as the elementary units of causality and locality has two primary implications for a causal model of quantum objects: (1) quantum objects run autonomously with system-state update frequencies based on their local proper times and with either no or minimal dependency on external parameters. (2) The laws of physics that describe global (but relativistic) interrelationships must be translated to a causal model of interactions between quantum objects and interactions between quantum objects and the space.
The enterprise to construct a local causal model of quantum theory (QT), including quantum field theory (QFT), resulted in the identification of "quantum objects" as the elementary units of causality and locality.Quantum objects are collections of particles (including single particles) whose collective dynamics and measurement results can only be described by the laws of QT/ QFT.Quantum objects run autonomously with system state update frequency based on their local proper time and with no or minimal dependency on external parameters.The autonomy of quantum objects necessitates well-defined causal interrelationships between quantum objects and spacetime: 1) Quantum objects are embedded in space and move within space.2) In the proposed causal model, the dynamics of space is triggered by the dynamics of the quantum objects.The causal model of QT/QFT assumes discretized spacetime similar to the spacetime of causal dynamical triangulation.
Ultimate goal of the work described in this paper has been the construction of a local causal model of quantum theory including quantum field theory.The original model has been refined in a number of refinement steps.As the so far latest refinement step, quantum loops are identified as the elementary processes of spacetime dynamics and quantum field dynamics.Quantum loops are processes that constitute quantum objects.In the causal model of quantum loops and quantum objects presented here, the collective behavioral processes involve the elementary units of spacetime and the associated elementary units of quantum of fields.As such, quantum loop processes are the sources of gravitational fields (i.e., spacetime curvature) and of the quantum objects (wave function).The model may be viewed as a derivative of loop quantum gravity, spin networks and causal dynamical triangulation, although significant deviations to these theories exist.The causal model of quantum loops is based on a causal model of spacetime dynamics where space (-time) consists of interconnected space points, each of which is connected to a small number of neighboring space points.The curvature of spacetime is expressed by the density of these space points and by the arrangement of the connections between them.The quantum loop emerges in a collective behavioral process from a collection of space points that carry energy and quantum field attributes.The paper is considered by the author to represent a fairly complete causal model, except for some processes whose detailed behaviour needs to be determined by use of further computer simulations.
This article presents an analysis of the extent to which local causal models or local realistic models of quantum theory (QT), including quantum field theory (QFT), are theoretically possible and practically feasible in light of the present state of these theories. Quantum physicists consider Bells famous inequality and its violation in experiments to be a strong indication that local realistic or local causal models of QT are not possible and that quantum theory as a whole is therefore not a local realistic or local causal theory. Based on a proposed definition of a "formal causal model" for a theory of physics (such as QT), this paper investigates the possibility of having a local causal model for QT. Areas of QT are identified in which the construction of a causal model is impeded because of deficiencies in the state of the respective theory. It is shown that the removal of the deficiencies can be achieved by the provision of a causal model. Whereas the construction of a causal model of QT, including QFT, appears to be feasible after the removal of certain deficiencies, the construction of a local (causal) model does not appear to be possible. As a consequence of the conclusion that local (causal) models of QT/QFT are not possible, if a strong interpretation of locality is assumed, a locality model is proposed in which the non-localities are confined to "quantum objects".
The non-localities in quantum theory (QT) (the most famous example is expressed in the violation of Bell's inequality in experiments) impede the construction of a local causal model of QT including quantum field theory (QFT).The laws of collective behavior may be considered to be types of non-local laws: laws that apply to the collection of system components as a whole.The article presents a proposal for the treatment of the non-localities that exist in QT/QFT by the concepts of collective behavior.The basic components of the collective behavior are the spatial elements of the causal model of QT/QFT proposed by the author.
Abstract Quantum mechanics and relativity are two of the most successful theoretical frameworks in modern physics, yet their conceptual foundations remain difficult to reconcile at the deepest level. Quantum theory describes physical systems through states, observables, probabilities, measurement contexts, superposition, entanglement, and nonclassical correlations. Relativity describes physical processes through space-time structure, causal order, invariant physical law, observer-dependent decomposition of time and space, and constraints on signal propagation. This article examines the conceptual relationship between quantum measurement, relativistic causality, and space-time description. The purpose is not to present a mathematical unification but to analyze how the two frameworks organize physical explanation differently and where their interpretive tensions arise. Special attention is given to the measurement problem, the status of quantum states, the role of observers and reference frames, the meaning of locality, the distinction between correlation and causal influence, and the challenge of describing quantum processes without privileging a single global time. The article argues that many apparent conflicts between quantum theory and relativity result from importing classical intuitions into domains where they no longer apply. Quantum entanglement does not permit controllable faster-than-light communication, yet it challenges classical separability. Relativity forbids superluminal signaling, yet it does not require that all physically meaningful correlations be reducible to local classical properties. Measurement introduces another difficulty because standard quantum theory often describes state update in a way that appears instantaneous, while relativistic space-time does not provide a universal present. The discussion develops a conceptual framework in which quantum measurement is treated as a physical interaction, relativistic causality as a constraint on operational influence, and space-time description as an organizing structure for events rather than a simple background stage. This analysis is relevant for quantum field theory, quantum information, relativistic quantum foundations, and future approaches to quantum gravity.
An operational development of quantum theory is presented, from general correlations through single-particle theories to elementary quantum field theory, with a focus throughout on causal relations. The objective is to establish the extent to which quantum theories are consistent with the principle of relativistic causality (that no two events separated by a distance greater than their separation in time multiplied by the speed of light may have a causal influence on each other) and to examine the assumptions that this analysis requires. To do this, it is necessary to pay particular attention to the notions of spatial location and measurement. It is found that in a relativistically causal theory, any measurement made in a finite spatial region must have the capacity for particle creation. A number of derivations are presented, including some relativistic single-particle propagators and a Hamiltonian based on the square root of the Klein Gordon equation.