716 research outputs found
Conformal Invariance in the Long-Range Ising Model
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)
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.
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
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 -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 -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
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
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
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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