1,597 research outputs found

    Religious Relationships with the Environment in a Tibetan Rural Community : Interactions and Contrasts with Popular Notions of Indigenous Environmentalism

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    Acknowledgments: We thank Beijing Forestry University, our field assistants Tashi Rabden, Pema Dechin, Tsewang Chomtso and Gele Chopel for their invaluable help, the Forest Bureau of Daocheng county for permission and support, and the people of Samdo for their hospitality and participation. The research was funded by the ESRC and the World Pheasant Association. This paper is a contribution to Imperial College’s Grand Challenges in Ecosystems and the Environment initiative. Two anonymous reviewers gave valuable comments on the manuscript.Peer reviewedPublisher PD

    The Efficacy of a Brief Behavioral Health Intervention for Managing High Utilization of ED Services by Chronic Pain Patients

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    Patients with chronic pain continue to seek medical care from emergency departments nationwide despite the fact that an emergency department is a less-than-optimal environment for meeting their specific and specialized needs. As the scientific community has gained a more sophisticated understanding of the mechanisms that contribute to the development and maintenance of chronic pain, the central role of psychological factors have emerged. Therefore, an ED-based, behavioral health intervention for chronic pain patients is needed to better serve this population and to help hospitals provide cost effective treatment at the appropriate level of care

    The Euler-Lagrange Cohomology and General Volume-Preserving Systems

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    We briefly introduce the conception on Euler-Lagrange cohomology groups on a symplectic manifold (M2n,ω)(\mathcal{M}^{2n}, \omega) and systematically present the general form of volume-preserving equations on the manifold from the cohomological point of view. It is shown that for every volume-preserving flow generated by these equations there is an important 2-form that plays the analog role with the Hamiltonian in the Hamilton mechanics. In addition, the ordinary canonical equations with Hamiltonian HH are included as a special case with the 2-form 1n1Hω\frac{1}{n-1} H \omega. It is studied the other volume preserving systems on (M2n,ω)({\cal M}^{2n}, \omega). It is also explored the relations between our approach and Feng-Shang's volume-preserving systems as well as the Nambu mechanics.Comment: Plain LaTeX, use packages amssymb and amscd, 15 pages, no figure

    Quantum Nature of the Big Bang: Improved dynamics

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    An improved Hamiltonian constraint operator is introduced in loop quantum cosmology. Quantum dynamics of the spatially flat, isotropic model with a massless scalar field is then studied in detail using analytical and numerical methods. The scalar field continues to serve as `emergent time', the big bang is again replaced by a quantum bounce, and quantum evolution remains deterministic across the deep Planck regime. However, while with the Hamiltonian constraint used so far in loop quantum cosmology the quantum bounce can occur even at low matter densities, with the new Hamiltonian constraint it occurs only at a Planck-scale density. Thus, the new quantum dynamics retains the attractive features of current evolutions in loop quantum cosmology but, at the same time, cures their main weakness.Comment: Typos corrected. Revised version to appear in Physical Review

    Color Skyrmions in the Quark-Gluon Plasma

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    We consider the general formulation of nonabelian fluid dynamics based on symmetry considerations. We point out that, quite generally, this admits solitonic excitations which are the color analog of skyrmions. Some general properties of the solitons are discussed.Comment: LaTeX, 13 pages, references adde

    A Comparative Study of Laplacians and Schroedinger-Lichnerowicz-Weitzenboeck Identities in Riemannian and Antisymplectic Geometry

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    We introduce an antisymplectic Dirac operator and antisymplectic gamma matrices. We explore similarities between, on one hand, the Schroedinger-Lichnerowicz formula for spinor bundles in Riemannian spin geometry, which contains a zeroth-order term proportional to the Levi-Civita scalar curvature, and, on the other hand, the nilpotent, Grassmann-odd, second-order \Delta operator in antisymplectic geometry, which in general has a zeroth-order term proportional to the odd scalar curvature of an arbitrary antisymplectic and torsionfree connection that is compatible with the measure density. Finally, we discuss the close relationship with the two-loop scalar curvature term in the quantum Hamiltonian for a particle in a curved Riemannian space.Comment: 55 pages, LaTeX. v2: Subsection 3.10 expanded. v3: Reference added. v4: Published versio

    Stargenfunctions, generally parametrized systems and a causal formulation of phase space quantum mechanics

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    We address the deformation quantization of generally parametrized systems displaying a natural time variable. The purpose of this exercise is twofold: first, to illustrate through a pedagogical example the potential of quantum phase space methods in the context of constrained systems and particularly of generally covariant systems. Second, to show that a causal representation for quantum phase space quasidistributions can be easily achieved through general parametrization. This result is succinctly discussed.Comment: 19 pages, to appear in J. Math. Phy

    Dimension of Conformal Blocks in Five Dimensional Kaehler-Chern-Simons Theory

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    We briefly review the Kaehler-Chern-Simon theory on 5-manifolds which are trivial circle bundles over 4-dimensional Kaehler manifolds and present a detailed calculation of the path integral, using the method of Blau and Thompson.Comment: 17 pages, typos corrected and minor corrections; the version to appear in Journal of Mathematical Physic

    Complete quantization of a diffeomorphism invariant field theory

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    In order to test the canonical quantization programme for general relativity we introduce a reduced model for a real sector of complexified Ashtekar gravity which captures important properties of the full theory. While it does not correspond to a subset of Einstein's gravity it has the advantage that the programme of canonical quantization can be carried out completely and explicitly, both, via the reduced phase space approach or along the lines of the algebraic quantization programme. This model stands in close correspondence to the frequently treated cylindrically symmetric waves. In contrast to other models that have been looked at up to now in terms of the new variables the reduced phase space is infinite dimensional while the scalar constraint is genuinely bilinear in the momenta. The infinite number of Dirac observables can be expressed in compact and explicit form in terms of the original phase space variables. They turn out, as expected, to be non-local and form naturally a set of countable cardinality.Comment: 32p, LATE
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