5,321 research outputs found

    Beyond the Standard Model for Montaneros

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    These notes cover (i) electroweak symmetry breaking in the Standard Model (SM) and the Higgs boson, (ii) alternatives to the SM Higgs boson including an introduction to composite Higgs models and Higgsless models that invoke extra dimensions, (iii) the theory and phenomenology of supersymmetry, and (iv) various further beyond topics, including Grand Unification, proton decay and neutrino masses, supergravity, superstrings and extra dimensions.Comment: Based on lectures by John Ellis at the 5th CERN-Latin-American School of High-Energy Physics, Recinto Quirama, Colombia, 15 - 28 Mar 2009, 84 pages, 35 figure

    Quadratic invariants for discrete clusters of weakly interacting waves

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    We consider discrete clusters of quasi-resonant triads arising from a Hamiltonian three-wave equation. A cluster consists of N modes forming a total of M connected triads. We investigate the problem of constructing a functionally independent set of quadratic constants of motion. We show that this problem is equivalent to an underlying basic linear problem, consisting of finding the null space of a rectangular M × N matrix with entries 1, −1 and 0. In particular, we prove that the number of independent quadratic invariants is equal to J ≡ N − M* ≄ N − M, where M* is the number of linearly independent rows in Thus, the problem of finding all independent quadratic invariants is reduced to a linear algebra problem in the Hamiltonian case. We establish that the properties of the quadratic invariants (e.g., locality) are related to the topological properties of the clusters (e.g., types of linkage). To do so, we formulate an algorithm for decomposing large clusters into smaller ones and show how various invariants are related to certain parts of a cluster, including the basic structures leading to M* < M. We illustrate our findings by presenting examples from the Charney–Hasegawa–Mima wave model, and by showing a classification of small (up to three-triad) clusters

    Criticality of Byproduct Materials: Assessing Supply Risk, Environmental Impact, and Strategic Policy Response for Tellurium

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    Creating a more sustainable future will require a transition toward more clean energy technologies. As technology shifts, the portfolio of materials needed to support the energy sector will shift as well. To prevent resource scarcity challenges, it is necessary to investigate multifaceted risks for energy materials. In recent years, a tool known as criticality assessment has been used for this purpose, identifying economic vulnerabilities for key energy, defense, and electronic technologies. These studies intend to guide strategic response to reduce risk; however existing methodologies lack a comprehensive systems perspective necessary to inform decisions. This is particularly true for materials supplied from byproduct mining. Byproduct minerals (e.g. tellurium, indium, gallium) are unintended minor joint products generated while mining and refining major metals (e.g. aluminum, iron, copper). They contribute only marginally to profit, so their extraction is justified strictly by association with the carrier metal ore, linking their supply, both physically and economically, to the system of materials being produced by the joint process. This level of interconnection is not well captured by the single-product focus characteristic of existing criticality assessments, potentially misrepresenting risks for byproducts. This dissertation aims to inform more appropriate policy response by addressing key gaps in criticality assessment and mitigation for byproduct minerals through the application of various systems modeling tools, including dynamic material flow analysis (dMFA), life cycle assessment (LCA), and scenario-based uncertainty analysis. Resulting contributions address the following specific challenges: (a) supply risk assessment neglects carrier metal production dynamics, (b) environmental risk assessment is sensitive to variability in impact allocation assumptions, and (c) standard, static result metrics are poorly matched for development of dynamic risk mitigation policy. Novel methodologies are demonstrated throughout using a case study of tellurium, a byproduct of copper refining critical to rapidly-growing CdTe thin-film photovoltaics

    En torno a las concepciones de la justicia

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    TeorĂ­a de la instituciĂłn

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    El derecho natural y sus tendencias actuales

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    Identification of new transitional disk candidates in Lupus with Herschel

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    New data from the Herschel Space Observatory are broadening our understanding of the physics and evolution of the outer regions of protoplanetary disks in star forming regions. In particular they prove to be useful to identify transitional disk candidates. The goals of this work are to complement the detections of disks and the identification of transitional disk candidates in the Lupus clouds with data from the Herschel Gould Belt Survey. We extracted photometry at 70, 100, 160, 250, 350 and 500 Ό\mum of all spectroscopically confirmed Class II members previously identified in the Lupus regions and analyzed their updated spectral energy distributions. We have detected 34 young disks in Lupus in at least one Herschel band, from an initial sample of 123 known members in the observed fields. Using the criteria defined in Ribas et al. (2013) we have identified five transitional disk candidates in the region. Three of them are new to the literature. Their PACS-70 Ό\mum fluxes are systematically higher than those of normal T Tauri stars in the same associations, as already found in T Cha and in the transitional disks in the Chamaeleon molecular cloud. Herschel efficiently complements mid-infrared surveys for identifying transitional disk candidates and confirms that these objects seem to have substantially different outer disks than the T Tauri stars in the same molecular clouds.Comment: Accepted for publication in A&A. 16 pages, 9 figures, 7 table

    Thermodynamics of a Colloidal Particle in a Time-Dependent Non-Harmonic Potential

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    We study the motion of an overdamped colloidal particle in a time-dependent non-harmonic potential. We demonstrate the first law-like balance between applied work, exchanged heat, and internal energy on the level of a single trajectory. The observed distribution of applied work is distinctly non-Gaussian in good agreement with numerical calculations. Both the Jarzynski relation and a detailed fluctuation theorem are verified with good accuracy
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