How to Be a Relationalist

Author(s):  
Shamik Dasgupta

Relationalism in metaphysics leads to indeterminism and non-locality in physics. This is widely thought to be a problem for relationalism, but here I argue that it is in fact a?virtue. More specifically, I distinguish two senses in which a physical theory can be indeterministic and non-local. Relationalism does imply indeterminism and non-locality in one sense, but this is a virtue since indeterminism and non-locality in this sense is precisely what empirical observation confirms. There is a second sense of the terms on which indeterminism and non-locality would be a problem, but I argue that relationalism does not imply indeterminism or non-locality in that sense. With respect to indeterminism and non-locality, then, relationalism gets things exactly right. This defense of relationalism rests on distinguishing these two senses of indeterminism and non-locality. Since both terms are intimately connected to metaphysical possibility, this requires distinguishing two species of the latter. The distinction between two senses of metaphysical possibility I offer may be of interest to metaphysicians regardless of its bearing on relationalism, determinism, and locality.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Edward Wheatcroft

Abstract A scoring rule is a function of a probabilistic forecast and a corresponding outcome used to evaluate forecast performance. There is some debate as to which scoring rules are most appropriate for evaluating forecasts of sporting events. This paper focuses on forecasts of the outcomes of football matches. The ranked probability score (RPS) is often recommended since it is ‘sensitive to distance’, that is it takes into account the ordering in the outcomes (a home win is ‘closer’ to a draw than it is to an away win). In this paper, this reasoning is disputed on the basis that it adds nothing in terms of the usual aims of using scoring rules. A local scoring rule is one that only takes the probability placed on the outcome into consideration. Two simulation experiments are carried out to compare the performance of the RPS, which is non-local and sensitive to distance, the Brier score, which is non-local and insensitive to distance, and the Ignorance score, which is local and insensitive to distance. The Ignorance score outperforms both the RPS and the Brier score, casting doubt on the value of non-locality and sensitivity to distance as properties of scoring rules in this context.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Marco Frasca ◽  
Anish Ghoshal

Abstract We investigate the non-perturbative regimes in the class of non-Abelian theories that have been proposed as an ultraviolet completion of 4-D Quantum Field Theory (QFT) generalizing the kinetic energy operators to an infinite series of higher-order derivatives inspired by string field theory. We prove that, at the non-perturbative level, the physical spectrum of the theory is actually corrected by the “infinite number of derivatives” present in the action. We derive a set of Dyson-Schwinger equations in differential form, for correlation functions till two-points, the solution for which are known in the local theory. We obtain that just like in the local theory, the non-local counterpart displays a mass gap, depending also on the mass scale of non-locality, and show that it is damped in the deep UV asymptotically. We point out some possible implications of our result in particle physics and cosmology and discuss aspects of non-local QCD-like scenarios.


Author(s):  
Nuel Belnap ◽  
Thomas Müller ◽  
Tomasz Placek

This book develops a rigorous theory of indeterminism as a local and modal concept. Its crucial insight is that our world contains events or processes with alternative, really possible outcomes. The theory aims at clarifying what this assumption involves, and it does it in two ways. First, it provides a mathematically rigorous framework for local and modal indeterminism. Second, we support that theory by spelling out the philosophically relevant consequences of this formulation and by showing its fruitful applications in metaphysics. To this end, we offer a formal analysis of modal correlations and of causation, which is applicable in indeterministic and non-local contexts as well. We also propose a rigorous theory of objective single-case probabilities, intended to represent degrees of possibility. In a third step, we link our theory to current physics, investigating how local and modal indeterminism relates to issues in the foundations of physics, in particular, quantum non-locality and spatio-temporal relativity. The book also ventures into the philosophy of time, showing how the theory’s resources can be used to explicate the dynamic concept of the past, present, and future based on local indeterminism.


Author(s):  
John Barnden

How, if at all, consciousness can be part of the physical universe remains a baffling problem. This article outlines a new, developing philosophical theory of how it could do so, and offers a preliminary mathematical formulation of a physical grounding for key aspects of the theory. Because the philosophical side has radical elements, so does the physical-theory side. The philosophical side is radical, first, in proposing that the productivity or dynamism in the universe that many believe to be responsible for its systematic regularities is actually itself a physical constituent of the universe, along with more familiar entities. Indeed, it proposes that instances of dynamism can themselves take part in physical interactions with other entities, this interaction then being “meta-dynamism” (a type of meta-causation). Secondly, the theory is radical, and unique, in arguing that consciousness is necessarily partly constituted of meta-dynamic auto-sensitivity, in other words it must react via meta-dynamism to its own dynamism, and also in conjecturing that some specific form of this sensitivity is sufficient for and indeed constitutive of consciousness. The article proposes a way for physical laws to be modified to accommodate meta-dynamism, via the radical step of including elements that explicitly refer to dynamism itself. Additionally, laws become, explicitly, temporally non-local in referring directly to quantity values holding at times prior to a given instant of application of the law. The approach therefore implicitly brings in considerations about what information determines states. Because of the temporal non-locality, and also because of the deep connections between dynamism and time-flow, the approach also implicitly connects to the topic of entropy insofar as this is related to time.


2019 ◽  
Vol 36 (15) ◽  
pp. 155006 ◽  
Author(s):  
A Belenchia ◽  
D Benincasa ◽  
F Marin ◽  
F Marino ◽  
A Ortolan ◽  
...  

2020 ◽  
Vol 10 (11) ◽  
pp. 3782 ◽  
Author(s):  
Abdel-Baset A. Mohamed ◽  
Ahmed Farouk ◽  
Mansour F. Yassen ◽  
Hichem Eleuch

In this paper, we analyze the dynamics of non-local correlations (NLCs) in an anisotropic two-qubit Heisenberg XYZ model under the effect of the phase damping. An analytical solution is obtained by applying a method based on the eigenstates and the eigenvalues of the Hamiltonian. It is observed that the generated NLCs are controlled by the Dzyaloshinskii–Moriya interaction, the purity indicator, the interaction with the environment, and the anisotropy. Furthermore, it is found that the quantum correlations, as well as the sudden death and sudden birth phenomena, depend on the considered physical parameters. In particular, the system presents a special correlation: the skew-information correlation. The log-negativity and the uncertainty-induced non-locality exhibit the sudden-change behavior. The purity of the initial states plays a crucial role on the generated nonlocal correlations. These correlations are sensitive to the DM interaction, anisotropy, and phase damping.


Author(s):  
Tadele Mengesha ◽  
Qiang Du

In this paper, the bond-based peridynamic system is analysed as a non-local boundary-value problem with volume constraint. The study extends earlier works in the literature on non-local diffusion and non-local peridynamic models, to include non-positive definite kernels. We prove the well-posedness of both linear and nonlinear variational problems with volume constraints. The analysis is based on some non-local Poincaré-type inequalities and the compactness of the associated non-local operators. It also offers careful characterizations of the associated solution spaces, such as compact embedding, separability and completeness. In the limit of vanishing non-locality, the convergence of the peridynamic system to the classical Navier equations of elasticity with Poisson ratio ¼ is demonstrated.


1993 ◽  
Vol 23 (3) ◽  
pp. 442-449 ◽  
Author(s):  
C.E. Van Wagner

Published data on two sets of experimental fires in jack pine (Pinusbanksiana Lamb.) forest were subjected to two forms of analysis. The first was a classification into surface fires and two kinds of crown fire, passive and active. In the second, the data were used to develop a model to predict both the spread rate of fire and the degree of crown consumption. The model consists mainly of two limiting equations for spread rate, one for surface fires and the other for full crowning fires; the independent variable is the Canadian Initial Spread Index. A critical surface intensity is first used to distinguish surface fires from crowning fires. A further process then estimates the degree of crowning and places the calculated final spread rate somewhere in the space between the limiting equations. The model inputs include six physical stand properties plus a pre-estimate of surface fuel consumption. It is a blend of physical theory and empirical observation.


Author(s):  
Ory Schnitzer ◽  
Vincenzo Giannini ◽  
Stefan A. Maier ◽  
Richard V. Craster

According to the hydrodynamic Drude model, surface plasmon resonances of metallic nanostructures blueshift owing to the non-local response of the metal’s electron gas. The screening length characterizing the non-local effect is often small relative to the overall dimensions of the metallic structure, which enables us to derive a coarse-grained non-local description using matched asymptotic expansions; a perturbation theory for the blueshifts of arbitrary-shaped nanometallic structures is then developed. The effect of non-locality is not always a perturbation and we present a detailed analysis of the ‘bonding’ modes of a dimer of nearly touching nanowires where the leading-order eigenfrequencies and eigenmode distributions are shown to be a renormalization of those predicted assuming a local metal permittivity.


Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 388
Author(s):  
Kosuke Mitarai ◽  
Keisuke Fujii

As the hardware technology for quantum computing advances, its possible applications are actively searched and developed. However, such applications still suffer from the noise on quantum devices, in particular when using two-qubit gates whose fidelity is relatively low. One way to overcome this difficulty is to substitute such non-local operations by local ones. Such substitution can be performed by decomposing a non-local channel into a linear combination of local channels and simulating the original channel with a quasiprobability-based method. In this work, we first define a quantity that we call channel robustness of non-locality, which quantifies the cost for the decomposition. While this quantity is challenging to calculate for a general non-local channel, we give an upper bound for a general two-qubit unitary channel by providing an explicit decomposition. The decomposition is obtained by generalizing our previous work whose application has been restricted to a certain form of two-qubit unitary. This work develops a framework for a resource reduction suitable for first-generation quantum devices.


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