¿Cómo ve la gente a la sociedad? : La estructura reticular de la opinión pública sobre conflictos sociales

Rusia y Costa Rica refuerza esta sorprendente conclusión. Otro resultado que estas encuestas producen es que las cuestiones "troncales", y las otras 50 a 70 cuestiones sobre conflicto social que constituyen el cuestionario cada año no tienen una estructura arbitraria que cambia de una encuesta a la otra. Las cuestiones "troncales" definen cada año una estructura reticular que se repite cada año con muy pocas modificaciones y que mediante sus vínculos (y oposiciones) define una estructura general con dos dimensiones fundamentales: en primer lugar, una oposición entre una postura abierta hacia la sociedad y sus problemas (los problemas sociales y conflictos de pueden manejar y solucionar) y una postura cerrada ("estábamos mejor en el pasado"); en segundo lugar, una oposición entre una reacción emotiva y una reacción no emotiva al conflicto social. Cada individuo o grupo social, posee una red de opiniones sobre conflicto social, opiniones que no son arbitrarias sino que están relacionadas unas con las otras de manera específica formando redes coherentes cuyos vínculos muestran una fuerte resistencia a la deformación por eventos externos. En resumen, las redes específicas de opinión sobre conflicto social se pueden asociar con individuos, grupos sociales o generaciones y los vínculos de la red muestran una fuerte resistencia al cambio a lo largo del tiempo. Hay incluso la posibilidad de medir la "resistencia" de estos vínculos reticulares.For the last twenty years, on a more-or-less annual basis, the French research organization, Agoram‚trie, has surveyed French public opinion on social conflicts. With a unique methodology involving the representative sampling of both the French population and French media discourse concerning social conflicts, a closed questionnaire is constructed and used to collect survey data which is then analyzed using principal component analysis, among other methods. The rather surprizing results of twenty years of research on the same topic are that a small set of approximately 40 "trunk" questions appear in each sampling of media coverage of social conflicts, independent of economic crises, national or political crises, or other environing events. These "trunk" questions -- such as "are there too many immigrant workers", "are doctors trust-worthy", "should women have the same rights as men", "are politicians corrupt" -- appear as basic human interrogations concerning society, and the use of the Agoram‚trie method in Great Britain, Russia and Costa Rica reinforces this surprizing conclusion. Another result that these surveys produced is that "trunk" questions, and the 50 to 70 other questions concerning social conflict which constitute the questionnaire each year, do not have an arbitrary structure which changes from one survey to the next. The "trunk" questions define each year a fundamental network structure that comes back with little modification each year, and in which ties -- and oppositions -- define an overall structure with two fundamental dimensions: first, an opposition between an ouverture toward society and its problems (social problems and conflicts can be addressed and dealt with) and closure ("we were better off in the past"); second, an opposition between emotive and non-emotive reactions to social conflict. Each individual, each social group, possesses a network of opinions on social conflicts, opinions that are not arbitrary but tied one to another to form specific, coherent networks whose ties show a strong resistant to deformation by external events. In short, specific networks of opinions on social conflict can be associated with individuals, social groups and generations, and the network ties show strong resistance to change over time. There is even the possibility of measuring the "resilience" of these network ties

General Relativistic Simulations of Magnetized Plasmas around Merging Supermassive Black Holes

Coalescing supermassive black hole binaries are produced by the mergers of galaxies and are the most powerful sources of gravitational waves accessible to space-based gravitational observatories. Some such mergers may occur in the presence of matter and magnetic fields and hence generate an electromagnetic counterpart. In this Letter, we present the first general relativistic simulations of magnetized plasma around merging supermassive black holes using the general relativistic magnetohydrodynamic code Whisky. By considering different magnetic field strengths, going from non-magnetically dominated to magnetically dominated regimes, we explore how magnetic fields affect the dynamics of the plasma and the possible emission of electromagnetic signals. In particular we observe a total amplification of the magnetic field of ~2 orders of magnitude which is driven by the accretion onto the binary and that leads to much stronger electromagnetic signals, more than a factor of 10^4 larger than comparable calculations done in the force-free regime where such amplifications are not possible.Comment: 7 pages, 5 figures. Minor changes to match version accepted for publication on The Astrophysical Journal Letter

A Measurement-Based Form of the Out-of-Place Quantum Carry Lookhead Adder

We present the design of aquantum carry-lookahead adder using measurement-based quantum computation.The quantum carry-lookahead adder (QCLA) is faster than aquantum ripple-carry adder; QCLA has logarithmic depth while ripple adders have linear depth. Our design is evaluated in terms of number of time steps, number of measurements, the total number of qubits used and the number of successful clustering operations required. Keyword : Quantum Carry-Lookahead Adder, Cluster-State Computatio

Quantum Estimation of Parameters of Classical Spacetimes

We describe a quantum limit to measurement of classical spacetimes. Specifically, we formulate a quantum Cramer-Rao lower bound for estimating the single parameter in any one-parameter family of spacetime metrics. We employ the locally covariant formulation of quantum field theory in curved spacetime, which allows for a manifestly background-independent derivation. The result is an uncertainty relation that applies to all globally hyperbolic spacetimes. Among other examples, we apply our method to detection of gravitational waves using the electromagnetic field as a probe, as in laser-interferometric gravitational-wave detectors. Other applications are discussed, from terrestrial gravimetry to cosmology.Comment: 23 pages. This article supersedes arXiv:1108.522

Arithmetic on a Distributed-Memory Quantum Multicomputer

We evaluate the performance of quantum arithmetic algorithms run on a distributed quantum computer (a quantum multicomputer). We vary the node capacity and I/O capabilities, and the network topology. The tradeoff of choosing between gates executed remotely, through ``teleported gates'' on entangled pairs of qubits (telegate), versus exchanging the relevant qubits via quantum teleportation, then executing the algorithm using local gates (teledata), is examined. We show that the teledata approach performs better, and that carry-ripple adders perform well when the teleportation block is decomposed so that the key quantum operations can be parallelized. A node size of only a few logical qubits performs adequately provided that the nodes have two transceiver qubits. A linear network topology performs acceptably for a broad range of system sizes and performance parameters. We therefore recommend pursuing small, high-I/O bandwidth nodes and a simple network. Such a machine will run Shor's algorithm for factoring large numbers efficiently.Comment: 24 pages, 10 figures, ACM transactions format. Extended version of Int. Symp. on Comp. Architecture (ISCA) paper; v2, correct one circuit error, numerous small changes for clarity, add reference

Layer by layer generation of cluster states

Cluster states can be used to perform measurement-based quantum computation. The cluster state is a useful resource, because once it has been generated only local operations and measurements are needed to perform universal quantum computation. In this paper, we explore techniques for quickly and deterministically building a cluster state. In particular we consider generating cluster states on a qubus quantum computer, a computational architecture which uses a continuous variable ancilla to generate interactions between qubits. We explore several techniques for building the cluster, with the number of operations required depending on whether we allow the ability to destroy previously created controlled-phase links between qubits. In the case where we can not destroy these links, we show how to create an n x m cluster using just 3nm -2n -3m/2 + 3 operations. This gives more than a factor of 2 saving over a naive method. Further savings can be obtained if we include the ability to destroy links, in which case we only need (8nm-4n-4m-8)/3 operations. Unfortunately the latter scheme is more complicated so choosing the correct order to interact the qubits is considerably more difficult. A half way scheme, that keeps a modular generation but saves additional operations over never destroying links requires only 3nm-2n-2m+4 operations. The first scheme and the last scheme are the most practical for building a cluster state because they split up the generation into the repetition of simple sections.Comment: 16 pages, 11 figure

Analyses of a Quarter of Century of Publishing at the BMS

Analyses d’un quart de siècle de publication au BMS: Le BMS a commencé à publier en octobre 1983 et, cent numéros plus tard, nous examinons les tentatives précédentes d’analyser le contenu du contenu des articles de recherche du journal. Dans ce numéro, nous analysons tous les articles de recherche et les rapports de recherche en cours publiés du numéro 1 au numéro 99 avec quatre méthodes différentes : une analyse par co-occurrence de mots clefs avec Calliope ; une classification hiérarchique ascendante et une descendante (Alceste) ; et une analyse factorielle des correspondances, Trideux. Les résultats de ces quatre analyses – publiés dans ce numéro du BMS – sont commentés et comparés entre eux, et aussi comparés avec les analyses précédentes du contenu du BMS.The BMS started publishing in October 1983 and, one hundred issues later, we look at previous attempts to analyze the content the journal’s research articles. With this issue, we analyze all the research articles and ongoing research reports published in issue 1 to issue 99 with four different methods: Calliope co-occurrence of key word analysis; a descending (Alceste) and an ascending hierarchical classification analysis; and Trideux correspondence analysis. The results of these four analyses – published in this issue of the BMS – are commented and compared between themselves, and compared with the previous analyses of BMS content