Distillation of genuine tripartite Einstein-Podolsky-Rosen steering

We show that a perfectly genuine tripartite EPR steerable assemblage can be distilled from partially genuine tripartite EPR steerable assemblages. In particular, we consider two types of hybrid scenarios: one-sided device-independent (1SDI) scenario (where one observer is untrusted, and other two observers are trusted) and two-sided device-independent (2SDI) scenario (where two observers are untrusted, and one observer is trusted). In both the scenarios, we show distillation of perfectly genuine steerable assemblage of three-qubit Greenberger-Horne-Zeilinger (GHZ) states or three-qubit W states from many copies of initial partially genuine steerable assemblages of the corresponding states. In each of these cases, we demonstrate that at least one copy of a perfectly genuine steerable assemblage can be distilled with certainty from infinitely many copies of initial assemblages. In case of practical scenarios employing finite copies, we show that the efficiency of our distillation protocols reaches near perfect levels using only a few number of initial assemblages

Measurement incompatibility and quantum advantage in communication

Measurement incompatibility stipulates the existence of quantum measurements that cannot be carried out simultaneously on single systems. We show that the set of input-output probabilities obtained from d -dimensional classical systems assisted with shared randomness is the same as the set obtained from d -dimensional quantum strategies restricted to compatible measurements with shared randomness in any communication scenario. Thus, measurement incompatibility is necessary for quantum advantage in communication, and any quantum advantage (with or without shared randomness) in communication acts as a witness to the incompatibility of the measurements at the receiver's end in a semi-device-independent way. We introduce a class of communication tasks—a general version of random access codes—to witness incompatibility of an arbitrary number of quantum measurements with arbitrary outcomes acting on d -dimensional systems and provide generic upper bounds on the success metric of these tasks for compatible measurements. We identify all sets of three incompatible rank-one projective qubit measurements that random access codes can witness. Finally, we present the generic relationship between different sets of probability distributions—classical, quantum with or without shared randomness, and quantum restricted to compatible measurements with or without shared randomness—produced in communication scenarios

Witnessing measurement incompatibility via communication tasks

Quantum theory offers measurement incompatibility, that is, the existence of quantum measurements that cannot be carried out simultaneously on single systems. Measurement incompatibility is essential for probing many aspects of quantum correlations and quantum information processing. However, its fundamental and generic link with nonclassical correlations observed in the simplest prepare-and-measure scenario is still untold. In the prepare-and-measure scenario, we uncover that d-dimensional classical systems assisted with shared randomness reproduce all the input-output statistics obtained from any set of d-dimensional compatible quantum measurements. Thus, any quantum advantage in one-way communication tasks with d-dimensional systems witnesses incompatibility of the measurements on the receiver's end in a semi-device-independent way. To witness incompatibility of an arbitrary number of quantum measurements acting on an arbitrary dimension, wherein different measurements have different outcomes, we introduce a class of communication tasks - a general version of random access codes. We provide generic upper bounds on the success metric of these tasks for compatible measurements. These bounds are tight whenever the dimension on which the measurements act is not larger than the number of outcomes of any of the measurements

Resource-theoretic efficacy of the single copy of a two-qubit entangled state in a sequential network

How best one can recycle a given quantum resource, mitigating the various difficulties involved in its preparation and preservation, is of considerable importance for ensuring efficient applications in quantum technology. Here, we demonstrate quantitatively the resource-theoretic advantage of reusing a single copy of a two-qubit entangled state toward information processing. To this end, we consider a scenario of sequential entanglement detection of a given two-qubit state by multiple independent observers on each of the two spatially separated wings. In particular, we consider equal numbers of sequential observers on the two wings. We first determine the upper bound on the number of observers who can detect entanglement employing suitable entanglement witness operators. In terms of the parameters characterizing the entanglement consumed and the robustness of measurements, we then compare the above scenario with the corresponding scenario involving multiple pairs of entangled qubits shared among the two wings. This reveals a clear resource-theoretic advantage of recycling a single copy of a two-qubit entangled state in the sequential network

Prioritizing Metro Service Quality Attributes to Enhance Commuter Experience: TOPSIS Ranking and Importance Satisfaction Analysis methods

A metro infrastructure, facility and service quality investigation based on commuter perception was conducted in this study to explore and prioritize the key attributes influencing overall metro service quality in typical Indian context. Based on the critical state of the art review, 12 key attributes were identified and they were accommodated in a paper based questionnaire to elicit commuter perception of importance and satisfaction by using a five point Likert scale. Subsequently, TOPSIS, an extensively adopted Multi attribute decision making technique, was carried out to rank the attributes with respect to perceived importance and satisfaction. Then an importance satisfaction analysis (ISA) was conducted to further classify the attributes in four quadrants based on their perceived degree of importance and satisfaction using an ISA matrix. Finally, the derived results from the TOPSIS and ISA analysis were combined and compared to obtain a prioritized set of attributes requiring intervention for better metro service quality in Indian context. Results of this study clearly indicated the relative strengths and weaknesses of each metro service/infrastructure specific attribute and presented the probable role of metro authorities for each of them. Attributes such as, Metro fare, Connection to metro and Metro frequency were observed to be the most important but were not performing satisfactorily, indicating that more emphasis is required on these attributes for improving the overall quality of travel by metro rail in Indian context. Hence, this methodology would be instrumental to detect a set of priority areas of improvement in metro rail service, which could contribute to retain the existing commuters and attract new metro users

Accretion, Primordial Black Holes and Standard Cosmology

Primordial Black Holes evaporate due to Hawking radiation. We find that the evaporation time of primordial black holes increase when accretion of radiation is included.Thus depending on accretion efficiency more and more number of primordial black holes are existing today, which strengthens the idea that the primordial black holes are the proper candidate for dark matter.Comment: 11 pages, 3 figure

Extension of non-minimal derivative coupling theory and Hawking radiation in black-hole spacetime

We study the greybody factor and Hawking radiation with a non-minimal derivative coupling between the scalar field and the curvature in the background of the slowly rotating Kerr-Newman black hole. Our results show that both the absorption probability and luminosity of Hawking radiation of the scalar field increase with the coupling. Moreover, we also find that for the weak coupling $\eta<\eta_c$, the absorption probability and luminosity of Hawking radiation decrease when the black hole's Hawking temperature decreases; while for stronger coupling $\eta>\eta_c$, the absorption probability and luminosity of Hawking radiation increase on the contrary when the black hole's Hawking temperature decreases. This feature is similar to the Hawking radiation in a $d$-dimensional static spherically-symmetric black hole surrounded by quintessence \cite{chensong}.Comment: 17 pages, 6 figures, 1 table, Title changed, Appendix changed, accepted by JHE

A Database of Domain Definitions for Proteins with Complex Interdomain Geometry

Protein structural domains are necessary for understanding evolution and protein folding, and may vary widely from functional and sequence based domains. Although, various structural domain databases exist, defining domains for some proteins is non-trivial, and definitions of their domain boundaries are not available. Here, we present a novel database of manually defined structural domains for a representative set of proteins from the SCOP “multi-domain proteins” class. (http://prodata.swmed.edu/multidom/). We consider our domains as mobile evolutionary units, which may rearrange during protein evolution. Additionally, they may be visualized as structurally compact and possibly independently folding units. We also found that representing domains as evolutionary and folding units do not always lead to a unique domain definition. However, unlike existing databases, we retain and refine these “alternate” domain definitions after careful inspection of structural similarity, functional sites and automated domain definition methods. We provide domain definitions, including actual residue boundaries, for proteins that well known databases like SCOP and CATH do not attempt to split. Our alternate domain definitions are suitable for sequence and structure searches by automated methods. Additionally, the database can be used for training and testing domain delineation algorithms. Since our domains represent structurally compact evolutionary units, the database may be useful for studying domain properties and evolution

Could dental school teaching clinics provide better care than regular private practices?

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149321/1/jicd12329.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149321/2/jicd12329_am.pd