Primordial Black Holes from Higgs Vacuum Instability: Avoiding Fine-tuning through an Ultraviolet Safe Mechanism

We have recently proposed the idea that dark matter in our universe is formed by primordial black holes generated by Standard Model Higgs fluctuations during inflation and thanks to the fact that the Standard Model Higgs potential develops an instability at a scale of the order of $10^{11}$ GeV. In this sense, dark matter does not need any physics beyond the Standard Model, although the mechanism needs fine-tuning to avoid the overshooting of the Higgs into the dangerous AdS vacuum. We show how such fine-tuning can be naturally avoided by coupling the Higgs to a very heavy scalar with mass $\gg 10^{11}$ GeV that stabilises the potential in the deep ultraviolet, but preserving the basic feature of the mechanism which is built within the Standard Model.Comment: 5 pages, 4 figure

Ultraviolet Properties of the Higgs Sector in the Lee-Wick Standard Model

The Lee-Wick (LW) Standard Model (SM) offers a new solution to the hierarchy problem. We discuss, using effective potential techniques, its peculiar ultraviolet (UV) behaviour. We show how quadratic divergences in the Higgs mass Mh cancel as a result of the unusual dependence of LW fields on the Higgs background (in a manner reminiscent of Little Higgses). We then extract from the effective potential the renormalization group evolution of the Higgs quartic coupling lambda above the LW scale. After clarifying an apparent discrepancy with previous results for the LW Abelian Higgs model we focus on the LWSM. In contrast with the SM case, for any Mh, lambda grows monotonically and hits a Landau pole at a fixed trans-Planckian scale (never turning negative in the UV). Then, the perturbativity and stability bounds on Mh disappear. We identify a cutoff ~10^{16} GeV for the LWSM due to the hypercharge gauge coupling hitting a Landau pole. Finally, we also discuss briefly the possible impact of the UV properties of the LW models on their behaviour at finite temperature, in particular regarding symmetry nonrestoration.Comment: 25 pages, 3 figure

A Note on Unparticle Decays

The coupling of an unparticle operator O_U to Standard Model particles opens up the possibility of unparticle decays into standard model fields. We study this issue by analyzing the pole structure (and spectral function) of the unparticle propagator, corrected to account for one-loop polarization effects from virtual SM particles. We find that the propagator of a scalar unparticle (of scaling dimension 1 < d_U < 2) with a mass gap m_g develops an isolated pole, m_p^2-i m_p Gamma_p, with m_p^2 < m_g^2 below the unparticle continuum that extends above m_g (showing that the theory would be unstable without a mass gap). If that pole lies below the threshold for decay into two standard model particles the pole corresponds to a stable unparticle state (and its width Gamma_p is zero). For m_p^2 above threshold the width is non zero and related to the unparticle decay rate into Standard Model particles. This picture is valid for any value of d_U in the considered range.Comment: 11 pages, 4 figure

"Things Japanese" by Basil H. Chamberlain: the first cultural guide to Japan?

Basil H. Chamberlain publicó en 1890 Things Japanese, un extenso libro con formato enciclopédico en el que recogía y describía rasgos culturales de Japón. El libro tuvo un gran éxito, y fue traducido por Gonzalo Jiménez de la Espada al español en la segunda década del siglo XX, si bien dicha traducción nunca vio la luz y se conservó solo parcialmente, hasta su recuperación en el año 2014. En este trabajo, analizamos “Cosas de Japón” como una primera guía cultural dirigida al turista culto de finales del siglo XIX y comienzos del XX. De forma particular, nos centramos en su título y en el concepto que articula el libro como una metáfora cognitiva sobre una cultura diferente, la japonesa: la idea de que Japón es un mundo topsy turvy, un mundo al revés. Indagamos en los orígenes de esa idea, existente ya en los tratados de Alessandro Valignano y, especialmente, de Luis Frois.In 1890, Basil H. Chamberlain published “Things Japanese”, an encyclopaedic book on Japan and its culture. The book enjoyed a formidable success and it was translated into Spanish during the second decade of the 20th century by Gonzalo Jiménez de la Espada, although that translation was never published and only survived partially, until its recovery in 2014. Here we analyse Cosas de Japón as one of the first cultural guides for the cultivated tourist of the late 19th and early 20th centuries. In particular, we focus on its title, and the central concept that articulates the book and serves as a cognitive metaphor about a different culture: the idea that Japan is a topsy turvy world, a world upside down. We investigate the origins of this idea, already present in works by Alessandro Valignano and, especially, Luis Frois

El orillero rioplatense. Arquetipo urbano en la ciudad moderna

Ponència presentada a: Session 3: Laboratorios de diseño innovador basado en la interacción humana / Laboratories for human centered innovative design interactio

Performance evaluation of space-time block coding using a realistic mobile radio channel

This paper presents a performance evaluation of space-time block coding (STBC) employing a realistic mobile radio channel model in macrocellular and urban environments. The bit error rate (BER) is computed by Monte-Carlo simulations in the down-link to evaluate its sensitivity to channel correlation. We consider a horizontal uniform linear array at the base station (BS) formed by up to four antenna elements, and one and two uncorrelated antenna elements at the mobile station (MS). The channel model includes the probability density function (pdf) of the azimuth and delay of the impinging waves and their expected power conditioned on the azimuth and delay. The statistical properties of the model are extracted from macrocellular measurements made in urban environments. Simulation results show that the use of STBC can provide significant gains with acceptable sensitivity to the channel correlation under realistic conditions.Peer ReviewedPostprint (published version

Aplicación de los modelos de crisis financiera de primera y segunda generación a la crisis financiera en Ecuador en el año 1999

The contemporary history of the Republic of Ecuador was marked undoubtedly by the financial crisis that hit the country in the last years of the 90s. This recession was characterized by a poor management of public policies and the deteriorating macroeconomic conditions, linked to the lack of confidence of economic agents that precipitated the withdrawal of the financial sector deposits. The economic literature on the origins and causes of financial crises and currency crisis is wide and is divided into three generations. The practical application of crisis models first and second generation 1999 Ecuador crisis allows us to understand the causes of it.La historia contemporánea de la República del Ecuador estuvo marcada sin duda alguna por la crisis financiera que azotó al país en los últimos años de la década de los 90s. Esta recesión estuvo marcada por un mal manejo de las políticas públicas y el deterioro de las condiciones macroeconómicas que, ligadas a la falta de confianza de los agentes económicos, precipitaron el retiro de los depósitos del sector financiero. La literatura económica sobre los orígenes y causas de las crisis financieras y cambiarias es amplia y está dividida en tres generaciones. La aplicación práctica de los modelos de crisis de primera y segunda generación a la crisis ecuatoriana de 1999 nos permite entender las causas de la misma

Learning to be a woman in the twentieth century Spain: a look from the Pedagogical Museum of the Faculty of Education at the University of Sevilla

La experiencia reseñada fue una iniciativa del Museo Pedagógico de la Facultad de CC. De la Educación de la Universidad de Sevilla, financiada por la Unidad de Igualdad de dicha Universidad e incluida en el programa de actividades didácticas que éste viene desarrollando desde sus inicios. Pensada para un variado público, su objetivo principal ha sido dar a conocer, de forma atractiva y reflexiva, la historia de la educación de las mujeres españolas del siglo XX, desde una perspectiva no victimista. El formato elegido fue el de una muestra expositiva combinada con un ciclo de conferencias, y rematada con una evaluación participativa y experiencial, lo que le proporcionó una mayor efectividad formativa. Su éxito ha asegurado la continuidad del proyecto para el curso próximo.The experience was an initiative outlined the Pedagogical Museum of the Faculty of Educational Sciences of the University of Seville, funded by the Equality Unit of the University and included in the program of educational activities it has developed since its inception. Designed for a diverse audience, its main aim has been to publicize, attractive and thoughtful way, the history of education of Spanish women of the twentieth century, from a non- victimization perspective. The format chosen was that of an exhibition shows combined with a series of lectures, and topped with a participatory and experiential evaluation, which provided increased training effectiveness. Its success has ensured the continuity of the project for next year