scholarly journals Postquantum common-cause channels: the resource theory of local operations and shared entanglement

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 419
Author(s):  
David Schmid ◽  
Haoxing Du ◽  
Maryam Mudassar ◽  
Ghi Coulter-de Wit ◽  
Denis Rosset ◽  
...  
Keyword(s):  
Systematic Study ◽  
Quantum Channel ◽  
Resource Theory ◽  
Valuable Resource ◽  
Common Cause ◽  
Special Cases ◽  
Common Causes ◽  
Different Types ◽  
Distributed Tasks

We define the type-independent resource theory of local operations and shared entanglement (LOSE). This allows us to formally quantify postquantumness in common-cause scenarios such as the Bell scenario. Any nonsignaling bipartite quantum channel which cannot be generated by LOSE operations requires a postquantum common cause to generate, and constitutes a valuable resource. Our framework allows LOSE operations that arbitrarily transform between different types of resources, which in turn allows us to undertake a systematic study of the different manifestations of postquantum common causes. Only three of these have been previously recognized, namely postquantum correlations, postquantum steering, and non-localizable channels, all of which are subsumed as special cases of resources in our framework. Finally, we prove several fundamental results regarding how the type of a resource determines what conversions into other resources are possible, and also places constraints on the resource's ability to provide an advantage in distributed tasks such as nonlocal games, semiquantum games, steering games, etc.

scholarly journals The type-independent resource theory of local operations and shared randomness

Quantum ◽  
2020 ◽  
Vol 4 ◽  
pp. 262 ◽  
Author(s):  
David Schmid ◽  
Denis Rosset ◽  
Francesco Buscemi
Keyword(s):  
Quantum Theory ◽  
Quantum Information Processing ◽  
Full Range ◽  
Quantum States ◽  
Resource Theory ◽  
Independent Manner ◽  
Common Cause ◽  
Entanglement Witnesses ◽  
Different Types ◽  
Common Resource

In space-like separated experiments and other scenarios where multiple parties share a classical common cause but no cause-effect relations, quantum theory allows a variety of nonsignaling resources which are useful for distributed quantum information processing. These include quantum states, nonlocal boxes, steering assemblages, teleportages, channel steering assemblages, and so on. Such resources are often studied using nonlocal games, semiquantum games, entanglement-witnesses, teleportation experiments, and similar tasks. We introduce a unifying framework which subsumes the full range of nonsignaling resources, as well as the games and experiments which probe them, into a common resource theory: that of local operations and shared randomness (LOSR). Crucially, we allow these LOSR operations to locally change the type of a resource, so that players can convert resources of any type into resources of any other type, and in particular into strategies for the specific type of game they are playing. We then prove several theorems relating resources and games of different types. These theorems generalize a number of seminal results from the literature, and can be applied to lessen the assumptions needed to characterize the nonclassicality of resources. As just one example, we prove that semiquantum games are able to perfectly characterize the LOSR nonclassicality of every resource of any type (not just quantum states, as was previously shown). As a consequence, we show that any resource can be characterized in a measurement-device-independent manner.

scholarly journals Using and reusing coherence to realize quantum processes

Quantum ◽  
2018 ◽  
Vol 2 ◽  
pp. 100 ◽  
Author(s):  
María García Díaz ◽  
Kun Fang ◽  
Xin Wang ◽  
Matteo Rosati ◽  
Michalis Skotiniotis ◽  
...  
Keyword(s):  
Coherent State ◽  
Quantum Channel ◽  
Resource Theory ◽  
Valuable Resource ◽  
Minimal Rank ◽  
Quantum Processes ◽  
Single Qubit ◽  
Degree Of Coherence ◽  
Constant Output ◽  
Resource State

Coherent superposition is a key feature of quantum mechanics that underlies the advantage of quantum technologies over their classical counterparts. Recently, coherence has been recast as a resource theory in an attempt to identify and quantify it in an operationally well-defined manner. Here we study how the coherence present in a state can be used to implement a quantum channel via incoherent operations and, in turn, to assess its degree of coherence. We introduce the robustness of coherence of a quantum channel-which reduces to the homonymous measure for states when computed on constant-output channels-and prove that: i) it quantifies the minimal rank of a maximally coherent state required to implement the channel; ii) its logarithm quantifies the amortized cost of implementing the channel provided some coherence is recovered at the output; iii) its logarithm also quantifies the zero-error asymptotic cost of implementation of many independent copies of a channel. We also consider the generalized problem of imperfect implementation with arbitrary resource states. Using the robustness of coherence, we find that in general a quantum channel can be implemented without employing a maximally coherent resource state. In fact, we prove that every pure coherent state in dimension larger than 2, however weakly so, turns out to be a valuable resource to implement some coherent unitary channel. We illustrate our findings for the case of single-qubit unitary channels.

Do Relative Status of Women and Marriage Characteristics Matter for the Intimate Partner Violence?

2021 ◽  
pp. 0192513X2110300
Author(s):  
Aysegul Kayaoglu
Keyword(s):  
Intimate Partner Violence ◽  
Partner Violence ◽  
Emotional Abuse ◽  
Intimate Partner ◽  
Resource Theory ◽  
Bargaining Model ◽  
Different Types ◽  
Relative Status ◽  
Turkish Case ◽  
Status Of Women

This article analyzes intimate partner violence (IPV) in a developing country context, namely, Turkey, which faces an enormous increase in femicide cases over the last decade. Analyzing a very rich nationwide representative survey on IPV, we show that it is not only the absolute status of women but also their relative status in terms of income and education that affects different types of domestic violence, ranging from emotional abuse to physical and sexual violence. Besides, factors related to marriage setting are found to have a significant role in the effect of women’s superior status on IPV. Overall, we provide evidence to support the relative resource theory and invalidate the intra-household bargaining model in the Turkish case.

Solution to time-energy costs of quantum channels

2015 ◽  
Vol 15 (7&8) ◽  
pp. 685-693
Author(s):  
Chi-Hang F. Fung ◽  
H. F. Chau ◽  
Chi-Kwong Li ◽  
Nung-Sing Sze
Keyword(s):  
Lower Bound ◽  
Semidefinite Programming ◽  
Energy Cost ◽  
Quantum Channel ◽  
Positive Semidefinite ◽  
Energy Costs ◽  
Quantum Channels ◽  
General Quantum ◽  
Special Cases

We derive a formula for the time-energy costs of general quantum channels proposed in [Phys. Rev. A {\bf 88}, 012307 (2013)]. This formula allows us to numerically find the time-energy cost of any quantum channel using positive semidefinite programming. We also derive a lower bound to the time-energy cost for any channels and the exact the time-energy cost for a class of channels which includes the qudit depolarizing channels and projector channels as special cases.

Circles on the Complex Plane

2021 ◽  
pp. 3-12
Author(s):  
A. Girsh
Keyword(s):  
Euclidean Space ◽  
Complex Plane ◽  
Euclidean Plane ◽  
Complex Space ◽  
Radical Center ◽  
Special Cases ◽  
Different Types ◽  
Different Dimensions ◽  
The Given ◽  
Made In

The Euclidean plane and Euclidean space themselves do not contain imaginary elements by definition, but are inextricably linked with them through special cases, and this leads to the need to propagate geometry into the area of imaginary values. Such propagation, that is adding a plane or space, a field of imaginary coordinates to the field of real coordinates leads to various variants of spaces of different dimensions, depending on the given axiomatics. Earlier, in a number of papers, were shown examples for solving some urgent problems of geometry using imaginary geometric images [2, 9, 11, 13, 15]. In this paper are considered constructions of orthogonal and diametrical positions of circles on a complex plane. A generalization has been made of the proposition about a circle on the complex plane orthogonally intersecting three given spheres on the proposition about a sphere in the complex space orthogonally intersecting four given spheres. Studies have shown that the diametrical position of circles on the Euclidean E-plane is an attribute of the orthogonal position of the circles’ imaginary components on the pseudo-Euclidean M-plane. Real, imaginary and degenerated to a point circles have been involved in structures and considered, have been demonstrated these circles’ forms, properties and attributes of their orthogonal position. Has been presented the construction of radical axes and a radical center for circles of the same and different types. A propagation of 2D mutual orthogonal position of circles on 3D spheres has been made. In figures, dashed lines indicate imaginary elements.

Fourth Nerve Palsy

2019 ◽  
pp. 105-110
Author(s):  
Matthew J. Thurtell ◽  
Robert L. Tomsak
Keyword(s):  
Nerve Palsy ◽  
Clinical Signs ◽  
Strabismus Surgery ◽  
Step Test ◽  
Management Options ◽  
Common Cause ◽  
Common Causes ◽  
The Common ◽  
Skew Deviation ◽  
Fourth Nerve Palsy

Fourth nerve palsy is a common cause of binocular vertical diplopia. However, it can be difficult to diagnose because the clinical signs are often subtle. In this chapter, we begin by reviewing the symptoms of fourth nerve palsy. We next discuss clinical maneuvers for diagnosing fourth nerve palsy, including the Parks-Bielschowsky three-step test. We list the common causes for isolated fourth nerve palsy and review its differential diagnosis, which includes skew deviation and myasthenia gravis. We then discuss the indications for neuroimaging in a patient with fourth nerve palsy. Lastly, we discuss management options for fourth nerve palsy, which include prisms and strabismus surgery.

Lightning and electrical injuries

2020 ◽  
pp. 1696-1700
Author(s):  
Chris Andrews
Keyword(s):  
Case Fatality ◽  
Open Water ◽  
Power Lines ◽  
Psychological Sequelae ◽  
Common Cause ◽  
Lightning Strikes ◽  
Pain Syndromes ◽  
Common Causes ◽  
Overhead Power Lines ◽  
Electrical Injuries

Lightning strikes are rare accidents but carry a 10% case fatality, killing 0.1–0.3 per million population each year. During thunderstorms, the risk is increased by sheltering under trees or by being on open water, on tractors, or in open fields or in outdoor activity. Lightning is considered to cause instant asystole. Immediate cardiopulmonary resuscitation is mandatory. Survivors might develop complications including pain syndromes and psychological sequelae. Burns are generally of minor consequence, unlike electrical injury. The most disabling consequences of the injury is generally the psychological sequelae. Meanwhile, electrocution is the fifth most common cause of workplace death, mainly affecting utilities, mining, and construction labourers. Domestic electrical accidents are common, where contact with overhead power lines, faulty power tools, and particularly using extension cords, are the most common causes, with metal ladders and antennae being particularly dangerous.

A Novel Approach for Analyzing Single Buffer Queueing Systems with State-Dependent Vacation and Correlated Input Process under Four Different Service Disciplines

2015 ◽  
Vol 6 (3) ◽  
pp. 19-59 ◽  
Author(s):  
Thomas Yew Sing Lee
Keyword(s):  
Performance Measures ◽  
Probability Generating Function ◽  
Performance Measure ◽  
Idle Time ◽  
Separate Analysis ◽  
Input Process ◽  
State Dependent ◽  
Special Cases ◽  
Service Disciplines ◽  
Different Types

The author presents performance analysis of a single buffer multiple-queue system. Four different types of service disciplines (i.e., non-preemptive, pre-emptive repeat different, state dependent random polling and globally gated) are analyzed. His model includes correlated input process and three different types of non-productive time (i.e., switchover, vacation and idle time). Special cases of the model includes server with mixed multiple and single vacations, stopping server with delayed vacation and stopping server with alternating vacation and idle time. For each of the four service disciplines the key performance measures such as average customer waiting time, loss probability, and throughput are computed. The results permit a detailed discussion of how these performance measures depends on the customer arrival rate, the customer service time, the switchover time, the vacation time, and the idle time. Moreover, extensive numerical results are presented and the four service disciplines are compared with respect to the performance measure. Previous studies of the single buffer multiple-queue systems tend to provide separate analysis for the two cases of zero and nonzero switchover time. The author is able to provide a unified analysis for the two cases. His results generalize and improve a number of known results on single buffer multiple-queue systems. Furthermore, this method does not require differentiation while it is needed if one uses the probability generating function approach. Lastly, the author's approach works for all single buffer multiple-queue systems in which the next queue to be served is determines solely on the basis of the occupancy states at the end of the cycle time.

scholarly journals Golgi Fragmentation in Neurodegenerative Diseases: Is There a Common Cause?

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 748 ◽  
Author(s):  
José Ángel Martínez-Menárguez ◽  
Mónica Tomás ◽  
Narcisa Martínez-Martínez ◽  
Emma Martínez-Alonso
Keyword(s):  
Neurodegenerative Diseases ◽  
Mammalian Cells ◽  
Early Event ◽  
Specific Group ◽  
Common Cause ◽  
Intracellular Traffic ◽  
Common Causes ◽  
Golgi Fragmentation ◽  
Complex Forms ◽  
Lateral Sclerosis

In most mammalian cells, the Golgi complex forms a continuous ribbon. In neurodegenerative diseases, the Golgi ribbon of a specific group of neurons is typically broken into isolated elements, a very early event which happens before clinical and other pathological symptoms become evident. It is not known whether this phenomenon is caused by mechanisms associated with cell death or if, conversely, it triggers apoptosis. When the phenomenon was studied in diseases such as Parkinson’s and Alzheimer’s or amyotrophic lateral sclerosis, it was attributed to a variety of causes, including the presence of cytoplasmatic protein aggregates, malfunctioning of intracellular traffic and/or alterations in the cytoskeleton. In the present review, we summarize the current findings related to these and other neurodegenerative diseases and try to search for clues on putative common causes.

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