716 research outputs found

    Conformal Invariance in the Long-Range Ising Model

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    We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.Comment: 52pp; V2: refs added; V3: ref added, published versio

    Hadronic and radiative three-body decays of J/psi involving the scalars f0(1370), f0(1500) and f0(1710)

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    We study the role of the scalar resonances f0(1370), f0(1500) and f0(1710) in the strong and radiative three-body decays of J/psi with J/psi to V + P P (gamma gamma) and J/psi to gamma + P P (V V), where P (V) denotes a pseudoscalar (vector) meson. We assume that the scalars result from a glueball-quarkonium mixing scheme while the dynamics of the transition process is described in an effective chiral Lagrangian approach. Present data on J/psi to V + P P are well reproduced, predictions for the radiative processes serve as further tests of this scenario.Comment: 15 page

    The S-matrix bootstrap. Part I : QFT in AdS.

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    We propose a strategy to study massive Quantum Field Theory (QFT) using conformal bootstrap methods. The idea is to consider QFT in hyperbolic space and study correlation functions of its boundary operators. We show that these are solutions of the crossing equations in one lower dimension. By sending the curvature radius of the background hyperbolic space to infinity we expect to recover flat-space physics. We explain that this regime corresponds to large scaling dimensions of the boundary operators, and discuss how to obtain the flat-space scattering amplitudes from the corresponding limit of the boundary correlators. We implement this strategy to obtain universal bounds on the strength of cubic couplings in 2D flat-space QFTs using 1D conformal bootstrap techniques. Our numerical results match precisely the analytic bounds obtained in our companion paper using S-matrix bootstrap techniques

    Massive Gravity Theories and limits of Ghost-free Bigravity models

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    We construct a class of theories which extend New Massive Gravity to higher orders in curvature in any dimension. The lagrangians arise as limits of a new class of bimetric theories of Lovelock gravity, which are unitary theories free from the Boulware-Deser ghost. These Lovelock bigravity models represent the most general non-chiral ghost-free theories of an interacting massless and massive spin-two field in any dimension. The scaling limit is taken in such a way that unitarity is explicitly broken, but the Boulware-Deser ghost remains absent. This automatically implies the existence of a holographic cc-theorem for these theories. We also show that the Born-Infeld extension of New Massive Gravity falls into our class of models demonstrating that this theory is also free of the Boulware-Deser ghost. These results extend existing connections between New Massive Gravity, bigravity theories, Galileon theories and holographic cc-theorems.Comment: 11+5 page

    Silages of agro-industrial by-products in lamb diets : effct on growth performance, carcass, meat quality and in vitro methane emissions

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    Research Areas: AgricultureABSTRACT - The use of agro-industrial by-products in animal feed is an opportunity to reduce imports, food waste and promote a clean and circular economy, turning worthless raw materials into high -quality and low-cost animal feeds, which does not compete with human food. This study aims to produce silages with by-products of carrot, sweet potato, potato, and tomato pomace and integrate them in lamb diets, replacing 50% of dry matter (DM) of a concentrate-based diet. Effects on growth performance, meat quality and methane production were evaluated. Three silages were produced using 350 g/kg tomato pomace, 200 g/kg wheat bran, 150 g/kg alfalfa hay and 300 g/kg potato (Psil) or 300 g/kg sweet potato (SPsil) or 300 g/kg carrot (Csil). Thirty-two lambs were housed individually and divided into four groups (8 animals/group) on the following diets: Control -850 g/kg concentrate and 150 g/kg hay; P -500 g/kg concentrate and 500 g/kg Psil in DM; SP - 500 g/kg concentrate and 500 g/kg SPsil in DM; C - 500 g/kg concentrate and 500 g/kg Csil in DM. The trial lasted 6 weeks after 1 week of adaptation. Methane production was assessed in vitro by the Ankom system, using as inoculum rumen content samples collected individually from 6 lambs on each diet at slaughter. Diet had no effect on DM intake, average daily gain and DM conversion ratio, averaging 1055 +/- 248 g, 320 +/- 61.1 g and 3.35 +/- 0.600, respectively. Also, carcass characteristics were not affected by the diet except for the lightness of subcutaneous fat which was increased by the silage diets (L* value, P = 0.016). The meat pa-rameters, pH, intramuscular fat, shear force, cooking losses and sensory attributes, were not affected by the diet. In meat color, the parameters a* and Chroma were highest in animals fed diet C, have an intermediate value with Control diet and are lowest with diets P and SP (P = 0.027 and P = 0.012, respectively). Diets had no impact on total methane emissions. The costs of the silage diets per kg live weight gain were lower than those of Control diet (P = 0.018). In summary, by-product silage can be a good option to replace concentrated feed in lamb diets without altering the growth performance and meat quality or methane production and thus contributing to the sustainability of livestock farms and the environment.info:eu-repo/semantics/publishedVersio

    PosterVote:expanding the action repertoire for local political activism

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    Online and digital technologies support and extend the action repertoires of localized social movements. In this paper we examine the ways by which digital technologies can support ‘on-the-ground ’ activist communities in the development of social movements. After identifying some of the challenges of deploying conventional voting and consultation technologies for activism, we examine situated political action in local communities through the design and deployment of a low-cost community voting prototype, PosterVote. We deploy PosterVote in two case studies with two local community organizations identifying the features that supported or hindered grassroots democratic practices. Through interviews with these communities, we explore the design of situated voting systems to support grassroots democratic practices and participation within an ecology of social action. Author Keywords Democracy; activism; participation; e-votin

    Experimental Evaluation of Innovative Wall Daylighting Systems

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    Daylighting offers the potential to save electrical energy and reduce peak demand for lighting, the major consumer of energy in a variety of buildings. However, widespread adoption of daylighting techniques is hampered by the lack of both daylight resource information and simple, reliable methods of testing daylighting designs. To surmount these obstacles, facilities for collecting illuminance data and for testing small-scale and full-size models have been established. These are (1) an extensively instrumented resource measurement station, (2) a sun angle simulator for exploring the geometries of the sun and the building during the early stages of design, (3) a heliodon to allow detailed illuminance and luminance distribution measurements in scale models, and (4) a rotating test building for quantitative and qualitative assessments of full-scale components. The current research efforts have been using these facilities to seek ways of projecting light admitted through walls deep into interior spaces. Sidelighting systems are of interest because the wall is the only available source of daylight in many commercial buildings. Innovative static and dynamic reflector assemblies have been examined and proven effective. Compared with typical sidelighting designs, the systems examined in this study project light deeper and produce more uniform illuminance across the space
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