scholarly journals Relativistic three-partite non-locality

2016 ◽  
Vol 14 (02) ◽  
pp. 1650008 ◽  
Author(s):  
Hooman Moradpour ◽  
Afshin Montakhab
Keyword(s):  
Spin Operator ◽  
Particle Systems ◽  
Moving Frame ◽  
W States ◽  
Relativistic Spin ◽  
Local Quantum ◽  
Different Types ◽  
Non Local ◽  
Pure States ◽  
Non Locality

Bell-like inequalities have been used in order to distinguish non-local quantum pure states by various authors. The behavior of such inequalities under Lorentz transformation (LT) has been a source of debate and controversies in the past. In this paper, we consider the two most commonly studied three-particle pure states, that of W and Greenberger–Horne–Zeilinger (GHZ) states which exhibit distinctly different types of entanglement. We discuss the various types of three-particle inequalities used in previous studies and point to their corresponding shortcomings and strengths. Our main result is that if one uses Czachor’s relativistic spin operator and Svetlichny’s inequality as the main measure of non-locality and uses the same angles in the rest frame (S) as well as the moving frame ([Formula: see text]), then maximally violated inequality in S will decrease in the moving frame, and will eventually lead to lack of non-locality (i.e. satisfaction of inequality) in the [Formula: see text] limit. This is shown for both the GHZ and W states and in two different configurations which are commonly studied (Cases 1 and 2). Our results are in line with a more familiar case of two particle case. We also show that the satisfaction of Svetlichny’s inequality in the [Formula: see text] limit is independent of initial particles’ velocity. Our study shows that whenever we use Czachor’s relativistic spin operator, results draws a clear picture of three-particle non-locality making its general properties consistent with previous studies on two-particle systems regardless of the W state or the GHZ state is involved. Throughout the paper, we also address the results of using Pauli’s operator in investigating the behavior of [Formula: see text] under LT for both of the GHZ and W states and two cases (Cases 1 and 2). Our investigation shows that the violation of [Formula: see text] in moving frame depends on the particle’s energy in the lab frame, which is in agreement with some previous works on two and three-particle systems. Our work may also help us to classify the results of using Czachor’s and Pauli’s operators to describe the spin entanglement and thus the system spin in relativistic information theory.

The accelerated Gisin state: its non-locality, quantum correlations and efficiency to perform quantum masking

2021 ◽  
Vol 21 (15&16) ◽  
pp. 1274-1295
Author(s):  
A.G. Abdelwahab ◽  
A. Ghwail ◽  
N. Metwally ◽  
M.H. Mahran ◽  
A. -S. F. Obada
Keyword(s):  
Quantum Correlations ◽  
Local Behavior ◽  
Quantum Uncertainty ◽  
Acceleration Parameter ◽  
Masking Condition ◽  
Local Quantum Uncertainty ◽  
Local Quantum ◽  
Non Local ◽  
Classical Correlations ◽  
Non Locality

The local and non local behavior of the accelerated Gisin state are investigated either before or after filtering process. It is shown that, the possibility of predicting the non-local behavior is forseen at large values of the weight of the Gisin and acceleration parameters. Due to the filtering process, the non-locality behavior of the Gisin state is predicted at small values of the weight parameter. The amount of non classical correlations are quantified by means of the local quantum uncertainty (LQU)and the concurrence, where the LQU is more sensitive to the non-locality than the concurrence. The phenomenon of the sudden changes is displayed for both quantifiers. Our results show that, the accelerated Gisin state could be used to mask information, where all the possible partitions of the masked state satisfy the masking criteria. Moreover, there is a set of states, which satisfy the masking condition, that is generated between each qubit and its masker qubit. For this set, the amount of the non-classical correlations increases as the acceleration parameter increases . Further, the filtering process improves these correlations, where their maximum bounds are much larger than those depicted for non-filtered states.

scholarly journals Non-local quantum electrodynamics admits a finitely induced gauge field action

1995 ◽  
Vol 451 (1943) ◽  
pp. 571-577 ◽  
Keyword(s):  
Gauge Field ◽  
Quantum Electrodynamics ◽  
Local Action ◽  
Four Dimensions ◽  
Field Action ◽  
Local Quantum ◽  
Non Local ◽  
Non Locality

This paper reconsiders a result obtained by Chrétien & Peierls within non-local quantum electrodynamics in four dimensions (1954, Proc. R. Soc. Lond . A 223, 468). Starting from secondly quantized fermions, subject to a non-local action with the kernel [i∂ x a ( x ) - mb ( x )] and gauge covariantly coupled to an external U ﴾1﴿ gauge field, they found that, for a = b , the induced gauge field action cannot be made finite, irrespective of the choice of the non-locality a (= b ﴿. But, the general case studied a ≠ b admits a finitely induced gauge field action, as the present paper demonstrates.

scholarly journals Evaluating probabilistic forecasts of football matches: the case against the ranked probability score

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Edward Wheatcroft
Keyword(s):  
Scoring Rules ◽  
Brier Score ◽  
Sporting Events ◽  
Forecast Performance ◽  
Scoring Rule ◽  
Probability Score ◽  
Probabilistic Forecasts ◽  
Non Local ◽  
Evaluating Forecasts ◽  
Non Locality

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.

Witnessing pairing correlations in identical-particle systems

2021 ◽  
Vol 21 (15&16) ◽  
pp. 1307-1319
Author(s):  
Cagan Aksak ◽  
Sadi Turgut
Keyword(s):  
Annihilation Operator ◽  
Identical Particle ◽  
Quantum Correlations ◽  
Particle Systems ◽  
Fermionic Systems ◽  
Different Types ◽  
Pairing Correlations

Quantum correlations and entanglement in identical-particle systems have been a puzzling question which has attracted vast interest and widely different approaches. Witness formalism developed first for entanglement measurement can be adopted to other kind of correlations. An approach is introduced by Kraus \emph{et al.}, [Phys. Rev. A \textbf{79}, 012306 (2009)] based on pairing correlations in fermionic systems and the use of witness formalism to detect pairing. In this contribution, a two-particle-annihilation operator is used for constructing a two-particle observable as a candidate witness for pairing correlations of both fermionic and bosonic systems. The corresponding separability bounds are also obtained. Two different types of separability definition are introduced for bosonic systems and the separability bounds associated with each type are discussed.

Relativistic Spin 4-vector and Spin Operator

2021 ◽  
Vol 71 (12) ◽  
pp. 1076-1081
Author(s):  
Yeong Deok HAN*
Keyword(s):  
Spin Operator ◽  
Relativistic Spin

scholarly journals Diluted mass gap in strongly coupled non-local Yang-Mills

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Marco Frasca ◽  
Anish Ghoshal
Keyword(s):  
Field Theory ◽  
Particle Physics ◽  
Mass Scale ◽  
Local Theory ◽  
Quantum Field ◽  
Strongly Coupled ◽  
Yang Mills ◽  
Mass Gap ◽  
Non Local ◽  
Non Locality

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.

scholarly journals Branching Space-Times

2021 ◽  
Author(s):  
Nuel Belnap ◽  
Thomas Müller ◽  
Tomasz Placek
Keyword(s):  
Single Case ◽  
Formal Analysis ◽  
Rigorous Theory ◽  
Quantum Non Locality ◽  
Foundations Of Physics ◽  
Local Contexts ◽  
Rigorous Framework ◽  
Non Local ◽  
Spatio Temporal ◽  
Non Locality

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.

scholarly journals The Meta-Dynamic Nature of Consciousness

2020 ◽  
Author(s):  
John Barnden
Keyword(s):  
Mathematical Formulation ◽  
Physical Universe ◽  
Time Flow ◽  
Non Local ◽  
Physical Interactions ◽  
Key Aspects ◽  
Physical Laws ◽  
The Universe ◽  
Non Locality ◽  
Do So

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.

scholarly journals Local and Non-Local Invasive Measurements on Two Quantum Spins Coupled via Nanomechanical Oscillations

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1078
Author(s):  
Dimitrios Maroulakos ◽  
Levan Chotorlishvili ◽  
Dominik Schulz ◽  
Jamal Berakdar
Keyword(s):  
Quantum Coherence ◽  
Indirect Measurement ◽  
Quantum Spin ◽  
Quantum States ◽  
Spin Interaction ◽  
First Case ◽  
Composite Quantum System ◽  
Local Quantum ◽  
Non Local ◽  
Quantum Spins

Symmetry plays the central role in the structure of quantum states of bipartite (or many-body) fermionic systems. Typically, symmetry leads to the phenomenon of quantum coherence and correlations (entanglement) inherent to quantum systems only. In the present work, we study the role of symmetry (i.e., quantum correlations) in invasive quantum measurements. We consider the influence of a direct or indirect measurement process on a composite quantum system. We derive explicit analytical expressions for the case of two quantum spins positioned on both sides of the quantum cantilever. The spins are coupled indirectly to each others via their interaction with a magnetic tip deposited on the cantilever. Two types of quantum witnesses can be considered, which quantify the invasiveness of a measurement on the systems’ quantum states: (i) A local quantum witness stands for the consequence on the quantum spin states of a measurement done on the cantilever, meaning we first perform a measurement on the cantilever, and subsequently a measurement on a spin. (ii) The non-local quantum witness signifies the response of one spin if a measurement is done on the other spin. In both cases the disturbance must involve the cantilever. However, in the first case, the spin-cantilever interaction is linear in the coupling constant Ω , where as in the second case, the spin-spin interaction is quadratic in Ω . For both cases, we find and discuss analytical results for the witness.

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