Irregular hypergeometric D-modules

We study the irregularity of hypergeometric D-modules $\mathcal{M}_A (\beta )$ via the explicit construction of Gevrey series solutions along coordinate subspaces in $X =\mathbb{C}^n$. As a consequence, we prove that along coordinate hyperplanes the combinatorial characterization of the slopes of $\mathcal{M}_A (\beta)$ given by M. Schulze and U. Walther in [21] still holds without any assumption on the matrix A. We also provide a lower bound for the dimensions of the spaces of Gevrey solutions along coordinate subspaces in terms of volumes of polytopes and prove the equality for very generic parameters. Holomorphic solutions outside the singular locus of $\mathcal{M}_A (\beta)$ can be understood as Gevrey solutions of order one along X at generic points and so they are included as a particular case.Comment: 41 pages; references, Remark 7.2. and 4 figures added; some comments changed; corrected typo

Weighted Hardy spaces associated with elliptic operators. Part I: Weighted norm inequalities for conical square functions

This is the first part of a series of three articles. In this paper, we obtain weighted norm inequalities for different conical square functions associated with the Heat and the Poisson semigroups generated by a second order divergence form elliptic operator with bounded complex coefficients. We find classes of Muckenhoupt weights where the square functions are comparable and/or bounded. These classes are natural from the point of view of the ranges where the unweighted estimates hold. In doing that, we obtain sharp weighted change of angle formulas which allow us to compare conical square functions with different cone apertures in weighted Lebesgue spaces. A key ingredient in our proofs is a generalization of the Carleson measure condition which is more natural when estimating the square functions below $p=2$

Characteristic cycles and Gevrey series solutions of AA-hypergeometric systems

We compute the $L$-characteristic cycle of an $A$-hypergeometric system and higher Euler-Koszul homology modules of the toric ring. We also prove upper semicontinuity results about the multiplicities in these cycles and apply our results to analyze the behavior of Gevrey solution spaces of the system.Comment: 22 page

- LEAST SQUARES ESTIMATES SYMETRICALLY ADJUSTED WITH NO LOSS OF INFORMATION IN THE TRUNCATED TOBIT MODEL

The objective of this paper is to improve the estimator of Powell (1986) in the truncated Tobit model. The Powell estimator is the least squares alternative to the maximum likelihood estimator for the Tobit model. Only symmetry of the distribution of the error term is assumed, but no distribution function is needed. In order to attain symmetry, our proposal predicts the values of the left hand side of the distribution, using the information contained in the right hand side, instead of eliminating sample information as the Powell estimator does. The paper takes an appropriate family of estimators as the point of departure, deriving the Power estimator as a particular case. The behaviour of the estimates of interest within thefamily is analysed both in terms of the theoretical properties and the small sample properties. El objetivo de este trabajo es mejorar el estimador propuesto por Powell (1986) para el modelo Tobit truncado. El estimador de Powell supone una alternativa al estimador máximo verosímil del modeloTobit y su ventaja es que no necesita admitir ninguna forma funcional conocida para la distribución deltérmino de error. La única hipótesis distribucional que se impone es la simetría. Para conseguir lasimetría, nuestra propuesta predice los valores de la cola inferior de la distribución, utilizando lainformación contenida en la cola derecha, en vez de eliminar información muestral como hace elestimador de Powell. El trabajo toma un adecuada familia de estimadores como punto de partida,derivando el estimador de Powell como un caso particular. Se analiza el comportamiento de losestimadores de interés dentro de la familia tanto en términos de propiedades teóricas comopropiedades en muestras finitas.Estimación semiparamétrica, modelo Tobit, regresión truncada Semiparametric estimation, Tobit model, truncated regression, Powell estimator

Characteristics of the english economic and finacial terms: a translational approach

En la actualidad, la traducción al español de los términos financieros anglosajones se ha centrado, fundamentalmente, en aquellos que se utilizan habitualmente en los mercados, debido a la gran importancia que estas instituciones han adquirido dentro de los sistemas económicos. No obstante, existe una parte de las Finanzas, la más próxima a la Teoría Económica, que no cuenta con unos corpus tan desarrollados como los primeros. Por ello, comenzaremos estudiando en profundidad las características generales de los términos financieros en inglés. Esta clasificación nos servirá como marco de referencia para el cumplimiento de los dos objetivos de este artículo. En primer lugar, pretendemos detectar las necesidades de traducción de los términos financieros más abstractos; y, en segundo lugar, ofrecer una propuesta de traducción de los mismos o de mayor información para los ya existentes. Para ello, este trabajo se sitúa en la corriente traduccional de la Terminología y pretende identificar algunas lagunas en el inglés financiero que requieren cierta intervención.G.I. HUM 767 (ayudas a Grupos de Investigación de la Junta de Andalucía) / Editorial Comares (colección interlingua

Internet of Things and Their Coming Perspectives: A Real Options Approach

Internet of things is developing at a dizzying rate, and companies are forced to implement it in order to maintain their operational efficiency. The high flexibility inherent to these technologies makes it necessary to apply an appropriate measure, which properly assesses risks and rewards. Real options methodology is available as a tool which fits the conditions, both economic and strategic, under which investment in internet of things technologies is developed. The contribution of this paper is twofold. On the one hand, it offers an adequate tool to assess the strategic value of investment in internet of things technologies. On the other hand, it tries to raise awareness among managers of internet of things technologies because of their potential to contribute to economic and social progress. The results of the research described in this paper highlight the importance of taking action as quickly as possible if companies want to obtain the best possible performance. In order to enhance the understanding of internet of things technologies investment, this paper provides a methodology to assess the implementation of internet of things technologies by using the real options approach; in particular, the option to expand has been proposed for use in the decision-making process