Random matrix study for a three-terminal chaotic device

We perform a study based on a random-matrix theory simulation for a three-terminal device, consisting of chaotic cavities on each terminal. We analyze the voltage drop along one wire with two chaotic mesoscopic cavities, connected by a perfect conductor, or waveguide, with one open mode. This is done by means of a probe, which also consists of a chaotic cavity that measure the voltage in different configurations. Our results show significant differences with respect to the disordered case, previously considered in the literature.Comment: Proccedings of the V Leopoldo Garcia-Colin Mexican Meeting on Mathematical and Experimental Physic

Prompt photon yield and v2v_2 coefficient from gluon fusion induced by magnetic field in heavy-ion collision

We compute the production of prompt photons and the $v_2$ harmonic coefficient in relativistic heavy-ion collisions induced by gluon fusion in the presence of an intense magnetic field, during the early stages of the reaction. The calculations take into account several parameters which are relevant to the description of the experimental transverse momentum distribution, and elliptic flow for RHIC and LHC energies. The main imput is the strength of the magnetic field which varies in magnitude from 1 to 3 times the pion mass squared, and allows the gluon fusion that otherwise is forbidden in the absence of the field. The high gluon occupation number and the value of the saturation scale also play an important role in our calculation, as well as a flow velocity and geometrical factors. Our results support the idea that the origin of at least some of the photon excess observed in heavy-ion experiments may arise from magnetic field induced processes, and gives a good description of the experimental data.Comment: 6 pages, 2 figures, conference paper from ISMD 201

Do foreign portfolio flows increase risk in emerging stock markets? Evidence from six Latin American countries

Foreign portfolio flows have been blamed for causing instability in emerging markets, especially during financial crises. This study measured the effect of foreign capital flows on volatility and exposure to world market risk in the six largest Latin American stock markets: Argentina, Brazil, Colombia, Chile, Mexico and Peru, for around 10 years including the 2008 World financial crisis. This will test whether these flows cause instability for those markets and increase their exposure to international stock market returns. A proprietary database, from Emerging Portoflio.com and time series models, both univariate (ARCH-GARCH) and multivariate (VAR), are used to estimate the effect foreign portfolio flows on the risk variables and the causality of these effects. We found no strong evidence to support the hypothesis that foreign flows cause instability in the Latin American stock markets, in spite of some evidence of causing price pressure. Instead, the evidence points to a strong dependence of market returns on international stock and foreign exchange markets, both in means and in volatility, instrumental to transmit crisis to those markets

Weak efficiency test in the colombian stock market

Este trabajo prueba la hipótesis de eficiencia débil al comprobar la hipótesis de martingala en diferencias en los retornos del Índice General de la Bolsa de Valores de Colombia, IGBC. Se considera una estructura de dependencia condicional de primer orden mediante el modelo auto-regresivo fraccionalmente integrado de medias móviles, ARFIMA, y de segundo orden con el modelo hiperbólico asimétrico potencial autorregresivo condicionalmente heterocedástico, HYAPARCH, el cual captura todos los hechos estilizados encontrados en la investigación empírica. Los resultados rechazan la hipótesis de eficiencia débil al mostrar que el proceso generador de los retornos parece obedecer a un modelo auto-regresivo fraccionalmente integrado, arfi, en media condicional y a un hiperbólico asimétrico autorregresivo condicionalmente heterocedástico, HYAGARCH, en varianza condicional.This paper proves the weak efficiency hypothesis when proving the maritingala hypothesis on return differences for the General Index of the Colombian Stock Exchange (IGBC) . A first order conditional dependency structure by using the Autoregressive Fractionally Integrated Moving Averages model ARFIMA, and on second order with the Hyperbolical Asymmetric Autoregressive Potential Conditionally Heteroscedastic model, HYAPARCH, which captures all the stylized facts in the empiric research is considered. The results reject the weak efficiency hypothesis when showing that the returns generation process seems to obey to and Autoregressive Fractionally Integrated model ARFI in conditional average anda Hyperbolical Asymmetric Conditionally Heteroscedastic model, HYAGARCH, in conditional variance.Este trabalho prova a hipótese de eficiência débil ao comprovar a hipótese de Gamarra em diferenças nas voltas do Índice Geral da Bolsa de Valores da Colômbia, IGBC. Considera-se uma estrutura de dependência condicional de primeiro ordem mediante o modelo Auto-regressivo Fraccionalmente Integrado de Médias Móveis,ARFIMA, e de segundo ordem com o modelo Hiperbólico Assimétrico Potencial Auto-regressivo Condicionalmente Heterocedástico, HYAPARCH, o qual captura todos os fatos estilizados encontrados na investigação empírica. Os resultados recusam a hipótese de eficiência débil ao mostrar que o processo gerador dasvoltas parece obedecer a um modelo Auto-regressivo Fraccionado Integrado, ARFI, em média condicional e a um Hiperbólico Assimétrico Auto-regressivo Condicionalmente Heterocedástico, HYAGARCH, em variância condiciona

Classification of pointed fusion categories of dimension p3p^3 up to weak Morita equivalence

We give a complete classification of pointed fusion categories over $\mathbb{C}$ of global dimension $p^3$ for $p$ any odd prime. We proceed to classify the equivalence classes of pointed fusion categories of dimension $p^3$ and we determine which of these equivalence classes have equivalent categories of modules

Multicultural education: some reflections on the spanish case

In this paper we succinctly describe sorne aspects related to multicultural education in Spain. First we must recognise that there exists a somewhat extensive and significant work on Gypsies (the most important ethnic group in Spain) that we do not include in this paper, because it would require a separate article. It is much more interesting, we hope, to present the state of art of discourses and practices related to multicultural education in our country. In fact, we argue Spanish authorities have never considered the education of Gypsy children as a matter of multicultural education. The very phrases 'multicultural education' and 'intercultural education' have only recently been introduced in Spain. In the first section of this paper we describe the reasons put forth by sorne authors to support intercultural education. Their rationale for more multicultural education is compared to our own reasons. Sections number two to five briefly review sorne congresses on multicultural education held in our country (II), current research (III), legislation (IV), and programs in action (V). The common feature of these sections is the emphasis on showing how scarce and recent the whole topic of multiculturalism is in Spain. However, many Spanish investigators and educators are beginning to work in thís fíeld, and government ínvolvement is rapidly growing

SYZ mirror symmetry for hypertoric varieties

We construct a Lagrangian torus fibration on a smooth hypertoric variety and a corresponding SYZ mirror variety using $T$-duality and generating functions of open Gromov-Witten invariants. The variety is singular in general. We construct a resolution using the wall and chamber structure of the SYZ base.Comment: v_2: 31 pages, 5 figures, minor revision. To appear in Communications in Mathematical Physic