Secure two-party quantum evaluation of unitaries against specious adversaries

We describe how any two-party quantum computation, specified by a unitary which simultaneously acts on the registers of both parties, can be privately implemented against a quantum version of classical semi-honest adversaries that we call specious. Our construction requires two ideal functionalities to garantee privacy: a private SWAP between registers held by the two parties and a classical private AND-box equivalent to oblivious transfer. If the unitary to be evaluated is in the Clifford group then only one call to SWAP is required for privacy. On the other hand, any unitary not in the Clifford requires one call to an AND-box per R-gate in the circuit. Since SWAP is itself in the Clifford group, this functionality is universal for the private evaluation of any unitary in that group. SWAP can be built from a classical bit commitment scheme or an AND-box but an AND-box cannot be constructed from SWAP. It follows that unitaries in the Clifford group are to some extent the easy ones. We also show that SWAP cannot be implemented privately in the bare model

Template-based Gravitational-Wave Echoes Search Using Bayesian Model Selection

The ringdown of the gravitational-wave signal from a merger of two black holes has been suggested as a probe of the structure of the remnant compact object, which may be more exotic than a black hole. It has been pointed out that there will be a train of echoes in the late-time ringdown stage for different types of exotic compact objects. In this paper, we present a template-based search methodology using Bayesian statistics to search for echoes of gravitational waves. Evidence for the presence or absence of echoes in gravitational-wave events can be established by performing Bayesian model selection. The Occam factor in Bayesian model selection will automatically penalize the more complicated model that echoes are present in gravitational-wave strain data because of its higher degree of freedom to fit the data. We find that the search methodology was able to identify gravitational-wave echoes with Abedi et al.'s echoes waveform model about 82.3% of the time in simulated Gaussian noise in the Advanced LIGO and Virgo network and about 61.1% of the time in real noise in the first observing run of Advanced LIGO with $\geq 5\sigma$ significance. Analyses using this method are performed on the data of Advanced LIGO's first observing run, and we find no statistical significant evidence for the detection of gravitational-wave echoes. In particular, we find $<1\sigma$ combined evidence of the three events in Advanced LIGO's first observing run. The analysis technique developed in this paper is independent of the waveform model used, and can be used with different parametrized echoes waveform models to provide more realistic evidence of the existence of echoes from exotic compact objects.Comment: 16 pages, 6 figure

The international right to health: what does it mean in legal practice and how can it affect priority setting for universal health coverage?

The international right to health is enshrined in national and international law. In a growing number of cases, individuals denied access to high-cost medicines and technologies under universal coverage systems have turned to the courts to challenge the denial of access as against their right to health. In some instances, patients seek access to medicines, services, or technologies that they would have access to under universal coverage if not for government, health system, or service delivery shortfalls. In others, patients seek access to medicines, services, or technologies that have not been included or that have been explicitly denied for coverage due to prioritization. In the former, judicialization of the right to health is critical to ensure patients access to the technologies or services to which they are entitled. In the latter, courts may grant patients access to medicines not covered as a result of explicit priority setting to allocate finite resources. By doing so, courts may give priority to those with the means and incentive to turn to the courts, at the expense of the maximization of equity- and population-based health. Evidence-based, informed decision-making processes could ensure that the most clinically and cost-effective products aligning with social value judgments are prioritized. Governments should be equipped to engage in and defend rational priority setting, and the priority setting process and institutions involved should be held accountable through an opportunity for appeal and judicial review. As a result, the courts could place greater reliance on the government's coverage choices, and the population's health could be most equitably distributed

On the communication cost of entanglement transformations

We study the amount of communication needed for two parties to transform some given joint pure state into another one, either exactly or with some fidelity. Specifically, we present a method to lower bound this communication cost even when the amount of entanglement does not increase. Moreover, the bound applies even if the initial state is supplemented with unlimited entanglement in the form of EPR pairs, and the communication is allowed to be quantum mechanical. We then apply the method to the determination of the communication cost of asymptotic entanglement concentration and dilution. While concentration is known to require no communication whatsoever, the best known protocol for dilution, discovered by Lo and Popescu [Phys. Rev. Lett. 83(7):1459--1462, 1999], requires a number of bits to be exchanged which is of the order of the square root of the number of EPR pairs. Here we prove a matching lower bound of the same asymptotic order, demonstrating the optimality of the Lo-Popescu protocol up to a constant factor and establishing the existence of a fundamental asymmetry between the concentration and dilution tasks. We also discuss states for which the minimal communication cost is proportional to their entanglement, such as the states recently introduced in the context of ``embezzling entanglement'' [W. van Dam and P. Hayden, quant-ph/0201041].Comment: 9 pages, 1 figure. Added a reference and some further explanations. In v3 some arguments are given in more detai

Interpretation and the Constraints on International Courts

This paper argues that methodologies of interpretation do not do what they promise – they do not constrain interpretation by providing neutral steps that one can follow in finding out a meaning of a text – but nevertheless do their constraining work by being part of what can be described as the legal practice

Implementasi Algoritma Kunang-Kunang Untuk Penjadwalan Mata Kuliah Di Universitas Ma Chung

. Course scheduling is considered as a complex matter because the generated schedule must guarantee that there are no clashes of classes, lecturers, and students’ schedules. At Ma Chung University, course scheduling is still accomplished manually. Due to the limited number of rooms and lecturers r, resource sharing system is applied. This causes complication in manual scheduling. Firefly algorithm is implemented in this application to schedule the course automatically. A schedule solution is represented as a firefly. Firefly with lower light intensity will move toward firefly with higher light intensity, so that a better solution is found. Based on a scheduling test, the best light intensity value of firefly is reached when firefly algorithm’s parameters, β0 and γ, are given 1 and 10 with light intensity value of 0,0003831