Local Causal Model Research Articles

The Generation of Quantum Objects by Quantum Loops

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.

A Local Causal Model of Spacetime Dynamics

The model of spacetime dynamics proposed here specifies how spacetime emerges, how changes of spacetime propagate, and how changes in spacetime arising from multiple sources accumulate. The overall goal of the model was to achieve maximum compatibility with general relativity and with Einstein’s equation; this goal appears to be achievable except at very small scales, where the discreteness of the units of space matters. The elementary structure of space(-time) that is assumed in this model is a derivative of causal dynamical triangulation. At the elementary level, space consists of a (discrete) number of interconnected space points, each of which is connected to a small number of neighbouring space points. The curvature of spacetime is expressed by the density of these space points and by the arrangement of the connections between them. Dynamics of spacetime (i.e., the emergence of space and the propagation of space changes) dynamically assigns “in-connections” and “out-connections” to the affected space points. Based on the model of the dynamics of curved discrete spacetime, a model of quantum field theory in curved discrete spacetime is described. Emergence and propagation of quantum fields (including particles) are mapped to the emergence and propagation of space changes by utilizing identical paths of in/out space point connections. Compatibility with standard quantum field theory requests the adjustment of the QFT techniques (e.g., Feynman diagrams, Feynman rules, creation/annihilation operators), which typically apply to three in/out connections, to n ＞3 in/out connections.

Collective Behavior in a Local Causal Model of Quantum Theory

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.

Spacetime Structures in a Causal Model of Quantum Theory

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.

Geometric Bell-like inequalities for steering

Many of the standard Bell inequalities (e.g., CHSH) are not effective for detection of quantum correlations which allow for steering, because for a wide range of such correlations they are not violated. We present Bell-like inequalities which have lower bounds for non-steering correlations than for local causal models. The inequalities involve all possible measurement settings at each side. We arrive at interesting and elegant conditions for steerability of arbitrary two-qubit states.

A probability loophole in the CHSH

In the present paper a robustness stress-test of the CHSH experiments for Einstein locality and causality is designed and employed. Random A and B from dice and coins, but based on a local model, run ”parallel” to a real experiment. We found a local causal model with a nonzero probability to violate the CHSH inequality for some relevant quartets Q of settings in the series of trials.

Scientific Coherence and the Fusion of Experimental Results

A pervasive feature of the sciences, particularly the applied sciences, is an experimental focus on a few (often only one) possible causal connections. At the same time, scientists often advance and apply relatively broad models that incorporate many different causal mechanisms. We are naturally led to ask whether there are normative rules for integrating multiple local experimental conclusions into models covering many additional variables. In this paper, we provide a positive answer to this question by developing several inference rules that use local causal models to place constraints on the integrated model, given quite general assumptions. We also demonstrate the practical value of these rules by applying them to a case study from ecology. 1. Experimental scope in applied sciences2. Fusing the results of experiments3. A concrete example of the inference rules4. Application to a case study

Operating procedure synthesis using local models and distributed goals

A strategy is proposed for the systematic synthesis of operating procedures for chemical processing systems which is based on modified means-ends analysis and planning with constraints. Planning issues arising from the use of distributed operating goals are addressed. A modelling method is presented which combines local causal models for identifying unit manipulations with numerical models to verify effects of process manipulations and to determine feasibility. The implementation of this strategy is illustrated with the planning of startup operations for a heat exchange network.