Gravity, p-branes and a spacetime counterpart of the Higgs effect

We point out that the worldvolume coordinate functions $\hat{x}^\mu(\xi)$ of a $p$-brane, treated as an independent object interacting with dynamical gravity, are Goldstone fields for spacetime diffeomorphisms gauge symmetry. The presence of this gauge invariance is exhibited by its associated Noether identity, which expresses that the source equations follow from the gravitational equations. We discuss the spacetime counterpart of the Higgs effect and show that a $p$-brane does not carry any local degrees of freedom, extending early known general relativity features. Our considerations are also relevant for brane world scenarios.Comment: 5 pages, RevTeX. v2 (30-IV-03) with additional text and reference

Modified spontaneous symmetry breaking pattern by brane-bulk interaction terms

We show how translational invariance can be broken by the vacuum that drives the spontaneous symmetry breaking of extra-dimensional extensions of the Standard Model, when delta-like interactions between brane and bulk scalar fields are present. We explicitly build some examples of vacuum configurations, which induce the spontaneous symmetry breaking, and have non trivial profile in the extra coordinate.Comment: 13 pages, two figure

Quantum Theory of Noncommutative Fields

Generalizing the noncommutative harmonic oscillator construction, we propose a new extension of quantum field theory based on the concept of "noncommutative fields". Our description permits to break the usual particle-antiparticle degeneracy at the dispersion relation level and introduces naturally an ultraviolet and an infrared cutoff. Phenomenological bounds for these new energy scales are given.Comment: LaTeX file, JHEP3.cls, subequations.sty; 12 pages, no figures. Final version published in JHEP with some references adde

Geotomography with solar and supernova neutrinos

We show how by studying the Earth matter effect on oscillations of solar and supernova neutrinos inside the Earth one can in principle reconstruct the electron number density profile of the Earth. A direct inversion of the oscillation problem is possible due to the existence of a very simple analytic formula for the Earth matter effect on oscillations of solar and supernova neutrinos. From the point of view of the Earth tomography, these oscillations have a number of advantages over the oscillations of the accelerator or atmospheric neutrinos, which stem from the fact that solar and supernova neutrinos are coming to the Earth as mass eigenstates rather than flavour eigenstates. In particular, this allows reconstruction of density profiles even over relatively short neutrino path lengths in the Earth, and also of asymmetric profiles. We study the requirements that future experiments must meet to achieve a given accuracy of the tomography of the Earth.Comment: 35 pages, 7 figures; minor textual changes in section

Electroweak Baryogenesis in Non-minimal Composite Higgs Models

We address electroweak baryogenesis in the context of composite Higgs models, pointing out that modifications to the Higgs and top quark sectors can play an important role in generating the baryon asymmetry. Our main observation is that composite Higgs models that include a light, gauge singlet scalar in the spectrum [as in the model based on the symmetry breaking pattern SO(6)/SO(5)], provide all necessary ingredients for viable baryogenesis. In particular, the singlet leads to a strongly first-order electroweak phase transition and introduces new sources of CP violation in dimension-five operators involving the top quark. We discuss the amount of baryon asymmetry produced and the experimental constraints on the model.Comment: 15 pages, 7 figure

Avaluació de paràmetres físics i químics de la mel mitjançant l’ús d’anàlisi de components principals

En el presente trabajo fueron evaluados los parámetros de las determinaciones analíticas de 23 muestras de mieles de origen natural de la Provincia de La Pampa (Argentina), utilizando análisis de componentes principales (PCA) como herramienta multivariada para la evaluación y análisis de los resultados. Se realizaron las siguientes determinaciones analíticas: pH, humedad, contenidos de azúcares reductores, sacarosa, HMF, acidez libre, acidez total y actividad diastásica de acuerdo a métodos oficiales. A través de los resultados obtenidos mediante PCA, se pueden explicar fenómenos que ocurren sobre las variables estudiadas, tales como el comportamiento de la actividad diastásica, las interacciones entre HMF y acidez e interacciones entre sacarosa y azúcares reductores, que permiten evaluar las relaciones existentes entre las distintas variables analizadas.In this work, the parameters of the analytic determinations in 23 naturals samples from the province of La Pampa (Argentina), were evaluated, using principal components analysis (PCA) as multivariate tool for the data evaluation and analysis of results. Were carried out the following analytic determinations: pH, humidity, reducer sugars, sucrose, HMF, free acidity, total acidity and diastasic activity, according to official methods. Through the results obtained by means of PCA, several phenomenas can be explained that happen on the studied variables, such as the diastasic activity behavior, interactions between HMF and acidity and interactions among sucrose and reducer sugars, that allow to evaluate the existent relationships among the analyzed variables.En el present treball, s’avaluen els paràmetres de les determinacions analítiques de 23 mostres de la Província de La Pampa (Argentina), utilitzant anàlisi de components principals (PCA) com a eines per a l’avaluació i anàlisi dels resultats. Es realitzen les següents determinacions analítiques: pH, humitat, continguts de sucres reductors, acidesa lliure, acidesa total i activitat diastàsica, emprant mètodes oficials. A partir dels PCA, es poden explicar fenòmens que es donen sobre les variables estudiades, com són el compost diastàsica, les interaccions entre HMF i acidesa, i les interaccions entre sacarosa i sucres avaluar les relacions existents entre les diferents variables analitzades.Fil: Lozano, V.A.. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Boeris, M.S.. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Scoles, Gladis Ester. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Pattacini, Silvia Haydeé. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Marchevsky, Eduardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Área de Química Analítica; ArgentinaFil: Camiña, José Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; Argentin

Inducing the cosmological constant from five-dimensional Weyl space

We investigate the possibility of inducing the cosmological constant from extra dimensions by embedding our four-dimensional Riemannian space-time into a five-dimensional Weyl integrable space. Following approach of the induced matter theory we show that when we go down from five to four dimensions, the Weyl field may contribute both to the induced energy-tensor as well as to the cosmological constant, or more generally, it may generate a time-dependent cosmological parameter. As an application, we construct a simple cosmological model which has some interesting properties.Comment: 7 page

Laboratory diagnosis of severe hypertriglyceridaemia. Cases from the dyslipidaemia regristy of the spanish atherosclerosis society

Background and Aims Severe hypertriglyceridaemia (sHTG) increases the risk of cardiovascular disease and acute pancreatitis episodes. Patients with sHTG fit mainly into two clinical entities: Familial or Multifactorial Chylomicronemia Syndromes (FCS and MCS, respectively). FCS and MCS exhibit clinical differences but also separate genetic and biochemical characteristics that can be assessed in the laboratory. The aim of this work has been to implement a laboratory workflow to help diagnose sHTG patients with either FCS or MCS. Methods Patients with two fasting triglycerides >1000mg/dL determinations were sequenced with a capture probe panel of 24 triglycerides-related genes using massive parallel sequencing (n=200). Two-step sequential ultracentrifugation was performed (n= 159) to diagnose Type I hyperlipoproteinemia (HLP I) and post heparin lipoprotein lipase activity was measured to discard or confirm its deficiency (n=60). Results Most patients had MCS as they: (i) did not exhibit HLPI and/or (ii) their genetic profile was not compatible with FCS and (iii) were not deficient in LPL activity. FCS cases were identified as they had: (i) HLPI, and/or (ii) biallelic pathogenic variants in LPL (n=5), GPIHBP1 (n=3), or LMF1 (n=2) genes and/or (iii) LPL activity deficiency. We identified 4 FCS patients with HLPI, biallelic pathogenic variants in APOA5 but a rescued LPL activity. An additional study of Apo-AV functionality was designed to confirm the FCS diagnosis in these cases. Conclusions Laboratory studies, in patients with severe hypertriglyceridaemia, provide with information of clinical utility to distinguish between Familial and Multifactorial Chylomicronemia Syndromes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech