11,643 research outputs found

    Circuit analysis of quantum measurement

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    We develop a circuit theory that enables us to analyze quantum measurements on a two-level system and on a continuous-variable system on an equal footing. As a measurement scheme applicable to both systems, we discuss a swapping state measurement which exchanges quantum states between the system and the measuring apparatus before the apparatus meter is read out. This swapping state measurement has an advantage in gravitational-wave detection over contractive state measurement in that the postmeasurement state of the system can be set to a prescribed one, regardless of the outcome of the measurement.Comment: 11pages, 7figure

    Ab-initio shell model with a core

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    We construct effective 2- and 3-body Hamiltonians for the p-shell by performing 12\hbar\Omega ab initio no-core shell model (NCSM) calculations for A=6 and 7 nuclei and explicitly projecting the many-body Hamiltonians onto the 0\hbar\Omega space. We then separate these effective Hamiltonians into 0-, 1- and 2-body contributions (also 3-body for A=7) and analyze the systematic behavior of these different parts as a function of the mass number A and size of the NCSM basis space. The role of effective 3- and higher-body interactions for A>6 is investigated and discussed

    Chameleon fields and solar physics

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    In this article we discuss some aspects of solar physics from the standpoint of the so-called chameleon fields (i.e. quantum fields, typically scalar, where the mass is an increasing function of the matter density of the environment). Firstly, we analyze the effects of a chameleon-induced deviation from standard gravity just below the surface of the Sun. In particular, we develop solar models which take into account the presence of the chameleon and we show that they are inconsistent with the helioseismic data. This inconsistency presents itself not only with the typical chameleon set-up discussed in the literature (where the mass scale of the potential is fine-tuned to the meV), but also if we remove the fine-tuning on the scale of the potential. Secondly, we point out that, in a model recently considered in the literature (we call this model "Modified Fujii's Model"), a conceivable interpretation of the solar oscillations is given by quantum vacuum fluctuations of a chameleon.Comment: 17 pages including figure

    Conceptual models of urban environmental information systems - toward improved information provision

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    Cities are the hub of European society - for over a millennium, they are the locus of social, political and economic development. As the core of intensive and creative human activity, they are also the place where the environmental externalities that accompany rapid development are most visible. The environmental consequences of urban development have been recognised long ago, as in the case of London, where in 1388 legislation was introduced to control pollutant emissions (Lowenthal, 1990). Similar historical environmental regulations can be demonstrated for many cities in Europe. However, while for most of history those who govern the city (be it the sovereign, city elders or local government) where responsible for the control, mitigation and management of the common environment in the city, the last 30 years are a period of profound change. This is due to the trend toward improved participation in environmental decision making . a more inclusive and open approach to decisions that deal with the city commons. This change did not occurre overnight but rather gradually. For example, in the United Kingdom, it was the Town and Country Planning Act of 1947 which introduced public scrutiny to changes in the urban form (Rydin, 1998), or the development of public involvement in environmental impact assessment of urban projects as developed in many countries throughout the developed world during the 1970s and 1980s (Gilpin 1995). These changes accelerate within the last three decades, and especially since the publication of .Our Common Future. (WCED and Brundtland 1987), the acceptance of the .Sustainable Development. principles and the Rio conference. A quiet (mini) revolution happened in Europe not long ago, toward the end of 1998 when the members of the United Nations Economic Commission for Europe (UN/ECE) signed the .Convention on Access to Information, Public Participation in Decision Making and Access to Justice in Environmental Matters. - the Aarhus Convention (UN/ECE 1998). The convention is expected to come into force by the end of 2001, and calls the governments and public authorities to open up access to environmental information as a means to improve public participation in environmental decision making and awareness of environmental issues (UN/ECE, 1998). However, these declarations on the value and importance of environmental information do not match our level of understanding on the role of environmental information in decision making processes, and especially on the role of information in improving awareness and participation. Therefore, it is useful to take a step back, and to try and evaluate how environmental information and access to it and its use support public involvement in such processes. This paper is aimed to offer a framework that can assist us in the analytical process of understanding environmental information use. It focuses on public access and assumes that environmental information will be delivered to the public through the Internet. Such assumption is based on the current trend within public authorities is to use Information and Communication Technology (ICT) as a major delivery medium and it seems that it will become more so in the near future (OECD 2000). The framework which this paper presents, is based on Soft Systems Methodology (SSM) study which unpacked some of the core issues relating to public access and use of environmental information (Haklay, 2001). Although the aim here is not to discuss the merits of SSM, but to focus on the conceptual models, some introduction to the techniques that are used here is needed. Therefore, the following section opens with introduction to SSM and its techniques. The core of the paper is dedicated to the development of conceptual models. After presenting the conceptual models, some conclusions about these models and their applications are drown

    Basic principles of SSM modelling: an examination of CATWOE from a soft perspective

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    This paper examines the SSM technique CATWOE, which focuses on defining necessary elements that together constitute a human activity system from a certain perspective. Despite its recognition within the literature and its numerous uses, there are few studies on how the technique can be improved. This research reflects on each of the elements both from a theoretical and a practical perspective. Findings point to the fact that some of the terms have a meaning in everyday language that differs from its definition within CATWOE. Other concepts are not well-defined. This is unfortunate and may both lead to misunderstandings and limit analysis. The paper points to a number of ways in which the use of CATWOE can be developed in order to further support the process of eliciting novel ideas for future actions. Hence, the overall conclusion is that the elements need to be rethought and some of them renamed

    On the extended Kolmogorov-Nagumo information-entropy theory, the q -> 1/q duality and its possible implications for a non-extensive two dimensional Ising model

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    The aim of this paper is to investigate the q -> 1/q duality in an information-entropy theory of all q-generalized entropy functionals (Tsallis, Renyi and Sharma-Mittal measures) in the light of a representation based on generalized exponential and logarithm functions subjected to Kolmogorov's and Nagumo's averaging. We show that it is precisely in this representation that the form invariance of all entropy functionals is maintained under the action of this duality. The generalized partition function also results to be a scalar invariant under the q -> 1/q transformation which can be interpreted as a non-extensive two dimensional Ising model duality between systems governed by two different power law long-range interactions and temperatures. This does not hold only for Tsallis statistics, but is a characteristic feature of all stationary distributions described by q-exponential Boltzmann factors.Comment: 13 pages, accepted for publication in Physica

    Goldstini

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    Supersymmetric phenomenology has been largely bound to the hypothesis that supersymmetry breaking originates from a single source. In this paper, we relax this underlying assumption and consider a multiplicity of sectors which independently break supersymmetry, thus yielding a corresponding multiplicity of goldstini. While one linear combination of goldstini is eaten via the super-Higgs mechanism, the orthogonal combinations remain in the spectrum as physical degrees of freedom. Interestingly, supergravity effects induce a universal tree-level mass for the goldstini which is exactly twice the gravitino mass. Since visible sector fields can couple dominantly to the goldstini rather than the gravitino, this framework allows for substantial departures from conventional supersymmetric phenomenology. In fact, this even occurs when a conventional mediation scheme is augmented by additional supersymmetry breaking sectors which are fully sequestered. We discuss a number of striking collider signatures, including various novel decay modes for the lightest observable-sector supersymmetric particle, gravitinoless gauge-mediated spectra, and events with multiple displaced vertices. We also describe goldstini cosmology and the possibility of goldstini dark matter.Comment: 14 pages, 7 figures; references adde

    Facial Expression Recognition

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