On the Complexity of Random Quantum Computations and the Jones Polynomial

There is a natural relationship between Jones polynomials and quantum computation. We use this relationship to show that the complexity of evaluating relative-error approximations of Jones polynomials can be used to bound the classical complexity of approximately simulating random quantum computations. We prove that random quantum computations cannot be classically simulated up to a constant total variation distance, under the assumption that (1) the Polynomial Hierarchy does not collapse and (2) the average-case complexity of relative-error approximations of the Jones polynomial matches the worst-case complexity over a constant fraction of random links. Our results provide a straightforward relationship between the approximation of Jones polynomials and the complexity of random quantum computations.Comment: 8 pages, 4 figure

Selling capitalism: The politics of white business in the 1980s

African Studies Seminar series. Paper presented March 1989Modern societies are faced with the problem of how to feed, house and ensure the well-being of their populations. They also confront the necessity of educating their work forces and dealing with those who are excluded from employment by reason of a shortage of opportunities, ill-health or old age. The responses to these requirements, however, display a considerable variety. In many of the countries of Western Europe, with Sweden at the forefront, the primary responsibility for welfare is borne by the state. In Japan, by contrast, occupational benefits constitute the dominant form of welfare provision. They figure prominently in the United States too, and represent a mode of supplying social services that the government of Singapore is eager to encourage. In Israel the trade union federation, the Histadrut, is centrally involved in the fields of medical care and pensions, whilst the Catholic Church in the Republic of Ireland is active in the sphere of education. In addition to the efforts of the public sector, of employers and of voluntary organisations, there is the private market, consisting in the buying and selling of goods and services either through insurance schemes or through direct payments by the consumer. Even Sweden, which has traditionally insisted on the exclusion of profit from welfare, has been affected by the contemporary shift in the direction of "privatisation," although in no way as severely as Britainor as Chile, an extreme case

Survey and analysis of research on supersonic drag-due-to-lift minimization with recommendations for wing design

A survey of research on drag-due-to-lift minimization at supersonic speeds, including a study of the effectiveness of current design and analysis methods was conducted. The results show that a linearized theory analysis with estimated attainable thrust and vortex force effects can predict with reasonable accuracy the lifting efficiency of flat wings. Significantly better wing performance can be achieved through the use of twist and camber. Although linearized theory methods tend to overestimate the amount of twist and camber required for a given application and provide an overly optimistic performance prediction, these deficiencies can be overcome by implementation of recently developed empirical corrections. Numerous examples of the correlation of experiment and theory are presented to demonstrate the applicability and limitations of linearized theory methods with and without empirical corrections. The use of an Euler code for the estimation of aerodynamic characteristics of a twisted and cambered wing and its application to design by iteration are discussed

Impérialisme américain : Des réalités passées aux prétextes présents

Cet article reprend la thèse avancée dans notre livre intitulé L’empire incohérent, où est présentée une analyse détaillée des pouvoirs militaire, politique, économique et idéologique des États-Unis, ainsi qu’une critique du nouvel impérialisme de l’administration Bush, en étudiant l’ensemble du règne de l’empire américain au cours des xxe et xxie siècles. Nous analyserons subséquemment les trois principales sous-catégories d’empire, ainsi qu’un autre type de domination essentiellement non impérial, soit les périodes d’impérialisme direct, indirect et informel, et l’hégémonie. Ces quatre dimensions font intervenir des niveaux décroissants de violence. Après avoir placé le nouvel impérialisme dans le contexte plus large des empires en général et de la longue trajectoire de l’impérialisme américain en particulier, nous en venons à analyser l’empire de Bush. Nous cherchons à répondre aux questions suivantes : où s’est située l’action des États-Unis dans cette typologie jusqu’à présent, à quel échelon de l’impérialisme s’est rendue l’administration de Bush fils, et quelles sont ses chances de succès ?Building on the argument laid out in our book Incoherent Empire, where we offered a detailed examination of the military, political, economic and ideological powers of the United States, as well as a critique of the new imperialism of the Bush administration, in this article, we refine the argument by surveying the whole course of American Empire throughout the 20th and 21st centuries. We subsequently address the three main sub-types of empire, plus one predominantly non-imperial type of domination : the periods of direct, indirect, and informal empire, and hegemony. These four involve declining levels of violence. After putting the new imperialism in broader context of empires in general and the long-term trajectory of American imperialism in particular we finally analyze the Bush empire. The questions we seek to answer here are : where has the United States fitted into this typology in the past ? How far has the administration of Bush the Younger imperially escalated ? And will this be successful