scholarly journals The causal order on the ambient boundary

2016 ◽  
Vol 31 (20) ◽  
pp. 1650122 ◽  
Author(s):  
Ignatios Antoniadis ◽  
Spiros Cotsakis ◽  
Kyriakos Papadopoulos
Keyword(s):  
Conformal Geometry ◽  
Causal Relation ◽  
Causal Structure ◽  
Causal Order ◽  
Poincaré Metric ◽  
Global Topology

We analyze the causal structure of the ambient boundary, the conformal infinity of the ambient (Poincaré) metric. Using topological tools, we show that the only causal relation compatible with the global topology of the boundary spacetime is the horismos order. This has important consequences for the notion of time in the conformal geometry of the ambient boundary.

scholarly journals Cyclic quantum causal models

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jonathan Barrett ◽  
Robin Lorenz ◽  
Ognyan Oreshkov
Keyword(s):  
Causal Reasoning ◽  
Causal Structure ◽  
Bell Inequalities ◽  
Quantum Correlations ◽  
Quantum Systems ◽  
Causal Models ◽  
Causal Order ◽  
Quantum Processes ◽  
Causal Explanations ◽  
Causal Structures

AbstractCausal reasoning is essential to science, yet quantum theory challenges it. Quantum correlations violating Bell inequalities defy satisfactory causal explanations within the framework of classical causal models. What is more, a theory encompassing quantum systems and gravity is expected to allow causally nonseparable processes featuring operations in indefinite causal order, defying that events be causally ordered at all. The first challenge has been addressed through the recent development of intrinsically quantum causal models, allowing causal explanations of quantum processes – provided they admit a definite causal order, i.e. have an acyclic causal structure. This work addresses causally nonseparable processes and offers a causal perspective on them through extending quantum causal models to cyclic causal structures. Among other applications of the approach, it is shown that all unitarily extendible bipartite processes are causally separable and that for unitary processes, causal nonseparability and cyclicity of their causal structure are equivalent.

The Metaphysics Of Freedom

1992 ◽  
Vol 22 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Fred Dretske
Keyword(s):  
Causal Relation ◽  
Causal Structure ◽  
Causal Chain ◽  
Human Freedom ◽  
Voluntary Action ◽  
Intentional Behavior

I offer Jimmy a dollar to wiggle his ears. He wiggles them because he wants the dollar and, as a result of my offer, thinks he will earn it by wiggling his ears. So I cause him to believe something that explains, or helps to explain, why he wiggles his ears. If I push a button, and a bell, wired to the button, rings because the button is depressed, I cause the bell to ring. I make it ring. Indeed, I ring it. So why don’t I, by offering him a dollar, make Jimmy wiggle his ears? Why, indeed, don’t I wiggle them? If I ring a bell by pushing a button, why don’t I wiggle Jimmy’s ears by offering him a dollar?That is a question that has always vexed a compatibilist’s vision of human freedom. If an intentional act–say, wiggling one’s ears in order to earn a dollar–is caused by one’s beliefs and desires (the reasons one has for wiggling one’s ears), then, by the transitivity of the causal relation, it appears to follow that it is (also) caused by whatever causes one to have those beliefs and desires. But the causes of belief and desire are often (in fact, if we trace the causal chain far enough backward, always) factors over which one has no control. So intentional behavior is often (or always) something one is made (caused) to do by factors over which one has no control. This, however, robs intentional behaviorand, presumably, also voluntary action–of its autonomy. Deliberate acts–Jimmy wiggling his ears to earn a dollar–have the same causal structure as does a bell that rings because a button is pushed. The only difference is the switch.

Perpetuity, Eternity, and Time in Proclus' Cosmos

Phronesis ◽  
2005 ◽  
Vol 50 (2) ◽  
pp. 150-169
Author(s):  
Helen Lang
Keyword(s):  
Causal Relation ◽  
Causal Structure ◽  
The Self ◽  
Precise Sense ◽  
The World ◽  
Effect Relation

AbstractProclus composed 18 arguments for the eternity of the world and they survive only because Philoponus, intending to refute Proclus' arguments one by one, quotes each; one copy of Philoponus' work – and so Proclus' arguments too – survives. Because of their odd history, these arguments have received little attention either in themselves or in relation to Proclus' other works, even though they are intrinsically interesting and reflect his larger philosophical enterprise. I first examine Argument XVIII, in which Proclus calls on "perpetuity", "eternity", and "time" to argue that the cosmos must be eternal. This argument leaves unanswered two important questions. The cosmos is caused by god and is itself a god; how can a cause and its effect both be gods? Proclus concludes that the cosmos is "a copy of the perpetuity of the eternal"; but what does this phrase – and the conclusion that it expresses – mean? To answer these questions, I turn to The Elements of Theology, a systematic progression of 211 propositions disclosing the causal structure of all reality. "Eternity" and "time", along with "being perpetual", also appear here, particularly in propositions 40-55, to which I turn in the second part of this paper. They are conjoined with what Proclus calls "the Self-Constituted". I argue that by understanding the relation of the Self-Constituted as a cause to its effect, what depends upon another, we can also understand the causal relation between god and the cosmos. The cosmos can be called divine because, via the cause/effect relation between them, god and the cosmos are both eternal; the cosmos is "a copy of the perpetuity of the eternal" because via its relation to god, the cosmos becomes what its cause is, and in this precise sense an effect "imitates" its cause.

scholarly journals The Discovery of Long-Run Causal Order: A Preliminary Investigation

Econometrics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 31
Author(s):  
Kevin D. Hoover
Keyword(s):  
Time Series ◽  
Causal Structure ◽  
Preliminary Investigation ◽  
Causal Modeling ◽  
Causal Order ◽  
Long Run ◽  
Weak Exogeneity

The relation between causal structure and cointegration and long-run weak exogeneity is explored using some ideas drawn from the literature on graphical causal modeling. It is assumed that the fundamental source of trending behavior is transmitted from exogenous (and typically latent) trending variables to a set of causally ordered variables that would not themselves display nonstationary behavior if the nonstationary exogenous causes were absent. The possibility of inferring the long-run causal structure among a set of time-series variables from an exhaustive examination of weak exogeneity in irreducibly cointegrated subsets of variables is explored and illustrated.

scholarly journals ASPECTS OF NONCOMMUTATIVE LORENTZIAN GEOMETRY FOR GLOBALLY HYPERBOLIC SPACETIMES

2003 ◽  
Vol 15 (10) ◽  
pp. 1171-1217 ◽  
Author(s):  
VALTER MORETTI
Keyword(s):  
Causal Structure ◽  
Order Relation ◽  
Partial Ordering ◽  
Lorentzian Geometry ◽  
Causal Order ◽  
C Algebra ◽  
Globally Hyperbolic ◽  
C Algebras ◽  
Hyperbolic Spacetime ◽  
Algebra Approach

Connes' functional formula of the Riemannian distance is generalized to the Lorentzian case using the so-called Lorentzian distance, the d'Alembert operator and the causal functions of a globally-hyperbolic spacetime. As a step of the presented machinery, a proof of the almost-everywhere smoothness of the Lorentzian distance considered as a function of one of the two arguments is given. Afterwards, using a C*-algebra approach, the spacetime causal structure and the Lorentzian distance are generalized into noncommutative structures giving rise to a Lorentzian version of part of Connes' noncommutative geometry. The generalized noncommutative spacetime consists of a direct set of Hilbert spaces and a related class of C*-algebras of operators. In each algebra a convex cone made of self-adjoint elements is selected which generalizes the class of causal functions. The generalized events, called loci, are realized as the elements of the inductive limit of the spaces of the algebraic states on the C*-algebras. A partial-ordering relation between pairs of loci generalizes the causal order relation in spacetime. A generalized Lorentz distance of loci is defined by means of a class of densely-defined operators which play the role of a Lorentzian metric. Specializing back the formalism to the usual globally-hyperbolic spacetime, it is found that compactly-supported probability measures give rise to a non-pointwise extension of the concept of events.

scholarly journals Genuinely multipartite noncausality

Quantum ◽  
2017 ◽  
Vol 1 ◽  
pp. 39 ◽  
Author(s):  
Alastair A. Abbott ◽  
Julian Wechs ◽  
Fabio Costa ◽  
Cyril Branciard
Keyword(s):  
Quantum Mechanics ◽  
Causal Structure ◽  
Matrix Formalism ◽  
Causal Order ◽  
Number Of Parties

The study of correlations with no definite causal order has revealed a rich structure emerging when more than two parties are involved. This motivates the consideration of multipartite "noncausal" correlations that cannot be realised even if noncausal resources are made available to a smaller number of parties. Here we formalise this notion: genuinely N-partite noncausal correlations are those that cannot be produced by grouping N parties into two or more subsets, where a causal order between the subsets exists. We prove that such correlations can be characterised as lying outside a polytope, whose vertices correspond to deterministic strategies and whose facets define what we call "2-causal" inequalities. We show that genuinely multipartite noncausal correlations arise within the process matrix formalism, where quantum mechanics holds locally but no global causal structure is assumed, although for some inequalities no violation was found. We further introduce two refined definitions that allow one to quantify, in different ways, to what extent noncausal correlations correspond to a genuinely multipartite resource.

scholarly journals Time-delocalized quantum subsystems and operations: on the existence of processes with indefinite causal structure in quantum mechanics

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 206 ◽  
Author(s):  
Ognyan Oreshkov
Keyword(s):  
Quantum Mechanics ◽  
Hilbert Spaces ◽  
Coherent Control ◽  
Causal Structure ◽  
Physical Realization ◽  
Causal Order ◽  
Quantum Processes ◽  
Standard Quantum ◽  
Novel Structure ◽  
The Times

It has been shown that it is theoretically possible for there to exist higher-order quantum processes in which the operations performed by separate parties cannot be ascribed a definite causal order. Some of these processes are believed to have a physical realization in standard quantum mechanics via coherent control of the times of the operations. A prominent example is the quantum SWITCH, which was recently demonstrated experimentally. However, the interpretation of such experiments as realizations of a process with indefinite causal structure as opposed to some form of simulation of such a process has remained controversial. Where exactly are the local operations of the parties in such an experiment? On what spaces do they act given that their times are indefinite? Can we probe them directly rather than assume what they ought to be based on heuristic considerations? How can we reconcile the claim that these operations really take place, each once as required, with the fact that the structure of the presumed process implies that they cannot be part of any acyclic circuit? Here, I offer a precise answer to these questions: the input and output systems of the operations in such a process are generally nontrivial subsystems of Hilbert spaces that are tensor products of Hilbert spaces associated with systems at different times---a fact that is directly experimentally verifiable. With respect to these time-delocalized subsystems, the structure of the process is one of a circuit with a causal cycle. This provides a rigorous sense in which processes with indefinite causal structure can be said to exist within the known quantum mechanics. I also identify a whole class of isometric processes, of which the quantum SWITCH is a special case, that admit a physical realization on time-delocalized subsystems. These results unveil a novel structure within quantum mechanics, which may have important implications for physics and information processing.

scholarly journals Causal Discovery in Radiographic Markers of Knee Osteoarthritis and Prediction for Knee Osteoarthritis Severity With Attention–Long Short-Term Memory

2020 ◽  
Vol 8 ◽  
Author(s):  
Yanfei Wang ◽  
Lei You ◽  
Jacqueline Chyr ◽  
Lan Lan ◽  
Weiling Zhao ◽  
...  
Keyword(s):  
Risk Factors ◽  
Knee Osteoarthritis ◽  
Joint Space Narrowing ◽  
Short Term Memory ◽  
Causal Relation ◽  
Causal Structure ◽  
Joint Space ◽  
Short Term ◽  
Term Memory ◽  
Long Short Term Memory

The goal of this study is to build a prognostic model to predict the severity of radiographic knee osteoarthritis (KOA) and to identify long-term disease progression risk factors for early intervention and treatment. We designed a long short-term memory (LSTM) model with an attention mechanism to predict Kellgren/Lawrence (KL) grade for knee osteoarthritis patients. The attention scores reveal a time-associated impact of different variables on KL grades. We also employed a fast causal inference (FCI) algorithm to estimate the causal relation of key variables, which will aid in clinical interpretability. Based on the clinical information of current visits, we accurately predicted the KL grade of the patient's next visits with 90% accuracy. We found that joint space narrowing was a major contributor to KOA progression. Furthermore, our causal structure model indicated that knee alignments may lead to joint space narrowing, while symptoms (swelling, grinding, catching, and limited mobility) have little impact on KOA progression. This study evaluated a broad spectrum of potential risk factors from clinical data, questionnaires, and radiographic markers that are rarely considered in previous studies. Using our statistical model, providers are able to predict the risk of the future progression of KOA, which will provide a basis for selecting proper interventions, such as proceeding to joint arthroplasty for patients. Our causal model suggests that knee alignment should be considered in the primary treatment and KOA progression was independent of clinical symptoms.

Special, radical, failure of reduction in psychiatry

2019 ◽  
Vol 42 ◽  
Author(s):  
Don Ross
Keyword(s):  
Mental Disorder ◽  
Brain Structure ◽  
Causal Structure ◽  
Network Models ◽  
Gambling Addiction ◽  
Brain Disorder ◽  
Mental Processes ◽  
Special Radical ◽  
Intentional Relationships

AbstractUse of network models to identify causal structure typically blocks reduction across the sciences. Entanglement of mental processes with environmental and intentional relationships, as Borsboom et al. argue, makes reduction of psychology to neuroscience particularly implausible. However, in psychiatry, a mental disorder can involve no brain disorder at all, even when the former crucially depends on aspects of brain structure. Gambling addiction constitutes an example.

Moving beyond the “LDL hypothesis”

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 333-340 ◽  
Author(s):  
Christian Werner ◽  
Ulrich Laufs
Keyword(s):  
Ldl Cholesterol ◽  
Causal Relation ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Clinical Trial Data ◽  
Randomised Clinical Trial ◽  
Trial Data ◽  
Low Density Lipoprotein Cholesterol ◽  
Genetic Studies ◽  
Statin Drug

Abstract. Summary: The term “LDL hypothesis” is frequently used to describe the association of low-density lipoprotein cholesterol (LDL-cholesterol, LDL-C) and cardiovascular (CV) events. Recent data from genetic studies prove a causal relation between serum LDL-C and CV events. These data are in agreement with mechanistic molecular studies and epidemiology. New randomised clinical trial data show that LDL-C lowering with statins and a non-statin drug, ezetimibe, reduces CV events. We therefore believe that the “LDL-hypothesis” has been proven; the term appears to be outdated and should be replaced by “LDL causality”.

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