Infinite-dimensional representations of the rotation group and Dirac's monopole problem

Within the context of infinite-dimensional representations of the rotation group the Dirac monopole problem is studied in details. Irreducible infinite-dimensional representations, being realized in the indefinite metric Hilbert space, are given by linear unbounded operators in infinite-dimensional topological spaces, supplied with a weak topology and associated weak convergence. We argue that an arbitrary magnetic charge is allowed, and the Dirac quantization condition can be replaced by a generalized quantization rule yielding a new quantum number, the so-called topological spin, which is related to the weight of the Dirac string.Comment: JHEP style. Extended version of hep-th/0403146. Revised version, title and some notations are changed. References and Appendix B are adde

The Inverse Scattering Method, Lie-Backlund Transformations and Solitons for Low-energy Effective Field Equations of 5D String Theory

In the framework of the 5D low-energy effective field theory of the heterotic string with no vector fields excited, we combine two non-linear methods in order to construct a solitonic field configuration. We first apply the inverse scattering method on a trivial vacuum solution and obtain an stationary axisymmetric two-soliton configuration consisting of a massless gravitational field coupled to a non-trivial chargeless dilaton and to an axion field endowed with charge. The implementation of this method was done following a scheme previously proposed by Yurova. We also show that within this scheme, is not possible to get massive gravitational solitons at all. We then apply a non-linear Lie-Backlund matrix transformation of Ehlers type on this massless solution and get a massive rotating axisymmetric gravitational soliton coupled to axion and dilaton fields endowed with charges. We study as well some physical properties of the constructed massless and massive solitons and discuss on the effect of the generalized solution generating technique on the seed solution and its further generalizations.Comment: 17 pages in latex, changed title, improved text, added reference

Design of a multi-point kinematic coupling for a high precision telescopic simultaneous measurement system

This paper covers the design of a new multi-point kinematic coupling specially developed for a high precision multi-telescopic arm measurement system for the volumetric verification of machine tools with linear and/or rotary axes. The multipoint kinematic coupling allows the simultaneous operation of the three telescopic arms that are registered at the same time to a sphere fixed on the machine tool spindle nose. Every coupling provides an accurate multi-point contact to the sphere, avoiding collisions and interferences with the other two multi-point kinematic couplings, and generating repulsion forces among them to ensure the coupling’s fingers interlacing along the machine tool x/y/z travels in the verification process. Simulation presents minimal deformation of the kinematic coupling under load, assuring the precision of the sphere-to-sphere distance meas-urement. Experimental results are provided to show that the multi-point kinematic coupling developed has repeatability values below ±1.2 µm in the application. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

γ\gamma - Z interferometry at a Φ\Phi-factory

We analyze the possibilities that the proposed $\Phi$-factories offer to measure $\gamma-Z$ interference. In the unpolarized beam case, we study different signatures in the $\rho \pi$ channel, taking advantage of the presence of the near-by $a_1$ resonance. We build a C-odd forward-backward asymmetry, estimated to be around $10^{-5}$, and (P-even, T-even) and (P-odd, T-odd) alignments of the $\rho$, to be seen from the angular distribution of its $\pi \pi$ decay products. With polarized electrons a left-right asymmetry around $2\times 10^{-4}$ is present in all channels. At leading order this asymmetry is independent of hadronic matrix elements and is sensitive to the $Z^0-s\bar{s}$ vector coupling. In the $\rho \pi$ channel, a combined left-right forward-backward asymmetry is considered.Comment: 29 pages + 6 figures. Some changes concerning $a_1$ observables, especially related with possible 2 $\gamma$ contribution

Metabolic syndrome before puberty: Myth or reality?

Metabolic syndrome (MetS) is defined as a cluster of alterations related with insulin resistance (obesity, dyslipidemia, hypertension, and impaired glucose metabolism), which are associated with a higher risk of cardiovascular disease in adults. Several definitions have been proposed for older children and adolescents. However, no definitions have been made in accordance with pubertal status, and those in prepubertal state have not received attention enough, despite there are data suggesting the early presence of risk factors. The new insights concerning healthy and unhealthy metabolic status or the addition of novel metabolic risk biomarkers, may contribute to the knowledge about the development of MetS in children. This manuscript reviews the available evidence on MetS during childhood, focusing on the prepubertal period

CP--Violating Invariants in Supersymmetry

I study the weak basis CP-violating invariants in supersymmetric models, in particular those which cannot be expressed in terms of the Jarlskog--type invariants, and find basis--independent conditions for CP conservation. With an example of the K-anti-K mixing, I clarify what are the combinations of supersymmetric parameters which are constrained by experiment.Comment: matches the PRD versio

3D heterotic string theory: new approach and extremal solutions

We develop a new formalism for the bosonic sector of low-energy heterotic string theory toroidally compactified to three dimensions. This formalism is based on the use of some single non-quadratic real matrix potential which transforms linearly under the action of subgroup of the three-dimensional charging symmetries. We formulate a new charging symmetry invariant approach for the symmetry generation and straightforward construction of asymptotically flat solutions. Finally, using the developed approach and the established formal analogy between the heterotic and Einstein-Maxwell theories, we construct a general class of the heterotic string theory extremal solutions of the Israel-Wilson-Perjes type. This class is asymptotically flat and charging symmetry complete; it includes the extremal solutions constructed before and possesses the non-trivial bosonic string theory limit.Comment: 20 pages in Late

Remote sensing for greenhouse detection from stereo pairs of WorldView-2 satellite

Revista oficial de la Asociación Española de Teledetección[EN] The successful launch of the first very high resolution (VHR) satellites capable of capturing panchromatic imagery of the land surface with ground sample distance even lower than 1 m (e.g. IKONOS in 1999 or QuickBird in 2001) marked the beginning of a wholly new age in remote sensing. On January 4, 2010, images of WorldView-2 were placed on the market. Possibly it is the most sophisticated commercial VHR satellite currently orbiting the Earth and the exploitation of its data poses a challenge to researchers worldwide. Moreover, the practice of under plastic agriculture had a great development in the Mediterranean area during the past 60 years, especially in Almeria, acting as a key economic driver in the area. The goal of this work is the automatic greenhouse mapping by using Object Based Image Analysis (OBIA). The required input data will be a pan-sharpened orthoimage and a normalized digital surface model (nDSM) for objects, both products generated from a WorldView-2 stereo pair. The attained results show that the very high resolution 8-band multispectral and the nDSM data improve the greenhouses automatic detection. In this way, overall accuracies higher than 90% can be achieved.[ES] El 4 de enero de 2010, se comenzaron a comercializar imágenes del satélite comercial de muy alta resolución (Very High Resolution; VHR) más sofisticado que actualmente orbita sobre la tierra. Se trata de WorldView-2, cuya resolución tanto geométrica (0.46 m y 1.84 m de tamaño de pixel en el nadir en la imagen pancromática y en la multiespectral respectivamente) como espectral (es el único satélite comercial VHR con 8 bandas en su imagen multiespectral) hacen que la explotación de sus datos suponga un verdadero desafío para investigadores de todo el mundo. Por otra parte, la práctica de la agricultura bajo plástico ha tenido un gran desarrollo en el área Mediterránea durante los últimos 60 años, especialmente en Almería, suponiendo un motor económico fundamental en la zona. El objetivo de este trabajo es la detección de invernaderos aplicando técnicas de análisis de imágenes basadas en objetos (OBIA). La información de base consistirá en una ortoimagen fusionada y datos de elevaciones de objetos, ambos productos obtenidos a partir de un estéreo par de imágenes del satélite de muy alta resolución WorldView-2. Los resultados obtenidos indican que el uso de las ocho bandas multiespectrales, junto a la inclusión de datos altimétricos mejoran las precisiones en la clasificación de invernaderos, pudiéndose obtener precisiones globales superiores al 90%.Este trabajo se ha desarrollado en el marco de los Proyecto del Plan Nacional de Investigación con referencias CTM2010-16573 y AGL2013- 42603-R, financiados por el Ministerio de Ciencia e Innovación del Gobierno de España y con fondos FEDER. El trabajo ha sido también cofinanciado mediante fondos FEDER a través del Programa de Cooperación Transfronteriza España-Fronteras Exteriores, POCTEFEX 2008-2013 (referencia 0065_COPTRUST_3_E). Los autores agradecen el apoyo de la Junta de Andalucía a través del Proyecto de Excelencia RNM-3575 y al Campus de Excelencia Internacional Agroalimentario ceiA3 (http://www.ceia3.es/).Aguilar, M.; Montalbán, M.; Saldaña, M.; Aguilar, F.; Fernández, I.; García-Lorca, A. (2014). Detección remota de invernaderos a partir de estéreo pares del satélite WorldView-2. Revista de Teledetección. (41):19-28. https://doi.org/10.4995/raet.2014.2288SWORD192841Espí, E., Salmerón, A., Fontecha, A., García, Y., & Real, A. I. (2006). PLastic Films for Agricultural Applications. Journal of Plastic Film & Sheeting, 22(2), 85-102. doi:10.1177/8756087906064220FAO, 2002. El cultivo protegido en clima mediterráneo. Estudio FAO Producción y Protección Vegetal 90, Organización de las Naciones Unidas para la Agricultura y la Alimentación, Roma.Torrens, M., 2006. El sector de Invernaderos en Marruecos. Instituto Espa-ol de Comercio Exterior (ICEX). Nota Sectorial, 15 pp

Solution of coupled vertex and propagator Dyson-Schwinger equations in the scalar Munczek-Nemirovsky model

In a scalar $\phi^2\chi$ model, we exactly solve the vertex and $\phi$ propagator Dyson-Schwinger equations under the assumption of a spatially constant (Munczek-Nemirovsky) propagator for the $\chi$ field. Various truncation schemes are also considered.Comment: 7 pages,4 figures, minor changes, reference added for published versio

The quadratic scalar radius of the pion and the mixed π−K\pi-K radius

We consider the quadratic scalar radius of the pion, , and the mixed $K-\pi$ scalar radius, . With respect to the second, we point out that the more recent (post-1974) experimental results in $K_{l3}$ decays imply a value, $=0.31\pm0.06 {\rm fm}^2$, which is about $2 \sigma$ above estimates based on chiral perturbation theory. On the other hand, we show that this value of suggests the existence of a low mass S$\tfrac{1}{2}$ $K\pi$ resonance. With respect to , we contest the central value and accuracy of current evaluations, that give $=0.61\pm0.04 {\rm fm}^2$. Based on experiment, we find a robust lower bound of $<r^2_{{\rm S},\pi}>\geq0.70\pm0.06 {\rm fm}^2$ and a reliable estimate, $<r^2_{{\rm S},\pi}>=0.75\pm0.07 {\rm fm}^2$, where the error bars are attainable. This implies, in particular, that the chiral result for $$ is $1.4 \sigma$ away from experiment. We also comment on implications about the chiral parameter $\bar{l}_4$, very likely substantially larger (and with larger errors) than usually assumed.Comment: PlainTeX file. Corrected asymptotic phase; numerical results unaffecte