1,311 research outputs found

    Approaches used to evaluate the social Impacts of protected areas

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    Protected areas are a key strategy in conserving biodiversity, and there is a pressing need to evaluate their social impacts. Though the social impacts of development interventions are widely assessed, the conservation literature is limited and methodological guidance is lacking. Using a systematic literature search, which found 95 relevant studies, we assessed the methods used to evaluate the social impacts of protected areas. Mixed methods were used by more than half of the studies. Almost all studies reported material aspects of wellbeing, particularly income; other aspects were included in around half of studies. The majority of studies provided a snapshot, with only one employing a before-after-control-intervention design. Half of studies reported respondent perceptions of impacts, while impact was attributed from researcher inference in 1/3 of cases. Although the number of such studies is increasing rapidly, there has been little change in the approaches used over the last 15 years, or in the authorship of studies, which is predominantly academics. Recent improvements in understanding of best practice in social impact evaluation need to be translated into practice if a true picture of the effects of conservation on local people is to be obtained

    Topological field theory and the quantum double of SU(2)

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    We study the quantum mechanics of a system of topologically interacting particles in 2+1 dimensions, which is described by coupling the particles to a Chern-Simons gauge field of an inhomogeneous group. Analysis of the phase space shows that for the particular case of ISO(3) Chern-Simons theory the underlying symmetry is that of the quantum double D(SU(2)), based on the homogeneous part of the gauge group. This in contrast to the usual q-deformed gauge group itself, which occurs in the case of a homogeneous gauge group. Subsequently, we describe the structure of the quantum double of a continuous group and the classification of its unitary irreducible representations. The comultiplication and the R-element of the quantum double allow for a natural description of the fusion properties and the nonabelian braid statistics of the particles. These typically manifest themselves in generalised Aharonov-Bohm scattering processes, for which we compute the differential cross sections. Finally, we briefly describe the structure of D(SO(2,1)), the underlying quantum double symmetry of (2+1)-dimensional quantum gravity.Comment: 48 pages, 3 figures, LaTeX2e; two remarks and a reference added, typos corrected; to appear in Nucl.Phys.

    Geometric quantization of completely integrable Hamiltonian systems in the action-angle variables

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    We provide geometric quantization of a completely integrable Hamiltonian system in the action-angle variables around an invariant torus with respect to polarization spanned by almost-Hamiltonian vector fields of angle variables. The associated quantum algebra consists of functions affine in action coordinates. We obtain a set of its nonequivalent representations in the separable pre-Hilbert space of smooth complex functions on the torus where action operators and a Hamiltonian are diagonal and have countable spectra.Comment: 8 page

    Non-linear finite WW-symmetries and applications in elementary systems

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    In this paper it is stressed that there is no {\em physical} reason for symmetries to be linear and that Lie group theory is therefore too restrictive. We illustrate this with some simple examples. Then we give a readable review on the theory finite WW-algebras, which is an important class of non-linear symmetries. In particular, we discuss both the classical and quantum theory and elaborate on several aspects of their representation theory. Some new results are presented. These include finite WW coadjoint orbits, real forms and unitary representation of finite WW-algebras and Poincare-Birkhoff-Witt theorems for finite WW-algebras. Also we present some new finite WW-algebras that are not related to sl(2)sl(2) embeddings. At the end of the paper we investigate how one could construct physical theories, for example gauge field theories, that are based on non-linear algebras.Comment: 88 pages, LaTe

    QUANTIZATION OF A CLASS OF PIECEWISE AFFINE TRANSFORMATIONS ON THE TORUS

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    We present a unified framework for the quantization of a family of discrete dynamical systems of varying degrees of "chaoticity". The systems to be quantized are piecewise affine maps on the two-torus, viewed as phase space, and include the automorphisms, translations and skew translations. We then treat some discontinuous transformations such as the Baker map and the sawtooth-like maps. Our approach extends some ideas from geometric quantization and it is both conceptually and calculationally simple.Comment: no. 28 pages in AMSTE

    Geometric Dequantization

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    Dequantization is a set of rules which turn quantum mechanics (QM) into classical mechanics (CM). It is not the WKB limit of QM. In this paper we show that, by extending time to a 3-dimensional "supertime", we can dequantize the system in the sense of turning the Feynman path integral version of QM into the functional counterpart of the Koopman-von Neumann operatorial approach to CM. Somehow this procedure is the inverse of geometric quantization and we present it in three different polarizations: the Schroedinger, the momentum and the coherent states ones.Comment: 50+1 pages, Late

    Mechanical similarity as a generalization of scale symmetry

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    In this paper we study the symmetry known as mechanical similarity (LMS) and present for any monomial potential. We analyze it in the framework of the Koopman-von Neumann formulation of classical mechanics and prove that in this framework the LMS can be given a canonical implementation. We also show that the LMS is a generalization of the scale symmetry which is present only for the inverse square potential. Finally we study the main obstructions which one encounters in implementing the LMS at the quantum mechanical level.Comment: 9 pages, Latex, a new section adde

    The "Symplectic Camel Principle" and Semiclassical Mechanics

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    Gromov's nonsqueezing theorem, aka the property of the symplectic camel, leads to a very simple semiclassical quantiuzation scheme by imposing that the only "physically admissible" semiclassical phase space states are those whose symplectic capacity (in a sense to be precised) is nh + (1/2)h where h is Planck's constant. We the construct semiclassical waveforms on Lagrangian submanifolds using the properties of the Leray-Maslov index, which allows us to define the argument of the square root of a de Rham form.Comment: no figures. to appear in J. Phys. Math A. (2002

    (2+1)D Exotic Newton-Hooke Symmetry, Duality and Projective Phase

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    A particle system with a (2+1)D exotic Newton-Hooke symmetry is constructed by the method of nonlinear realization. It has three essentially different phases depending on the values of the two central charges. The subcritical and supercritical phases (describing 2D isotropic ordinary and exotic oscillators) are separated by the critical phase (one-mode oscillator), and are related by a duality transformation. In the flat limit, the system transforms into a free Galilean exotic particle on the noncommutative plane. The wave equations carrying projective representations of the exotic Newton-Hooke symmetry are constructed.Comment: 30 pages, 2 figures; typos correcte

    Toeplitz Quantization of K\"ahler Manifolds and gl(N)gl(N) N→∞N\to\infty

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    For general compact K\"ahler manifolds it is shown that both Toeplitz quantization and geometric quantization lead to a well-defined (by operator norm estimates) classical limit. This generalizes earlier results of the authors and Klimek and Lesniewski obtained for the torus and higher genus Riemann surfaces, respectively. We thereby arrive at an approximation of the Poisson algebra by a sequence of finite-dimensional matrix algebras gl(N)gl(N), N→∞N\to\infty.Comment: 17 pages, AmsTeX 2.1, Sept. 93 (rev: only typos are corrected
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