Local Cohomology and non commutative Gorenstein algebras

In this paper we continue the study of non connected graded Gorenstein algebras initiated in a previous paper, the main result is the proof of a version of the Local Cohomology formula

Skew group algebras, invariants and Weyl Algebras

The aim of this paper is two fold: First to study finite groups $G$ of automorphisms of the homogenized Weyl algebra $B_{n}$, the skew group algebra $B_{n}\ast G$, the ring of invariants $B_{n}^{G}$, and the relations of these algebras with the Weyl algebra $A_{n}$, with the skew group algebra $A_{n}\ast G$, and with the ring of invariants $A_{n}^{G}$. Of particular interest is the case $n=1$. In the on the other hand, we consider the invariant ring \QTR{sl}{C}[X]^{G} of the polynomial ring $K[X]$ in $n$ generators, where $G$ is a finite subgroup of Gl(n,\QTR{sl}{C}) such that any element in $G$ different from the identity does not have one as an eigenvalue. We study the relations between the category of finitely generated modules over \QTR{sl}{C}[X]^{G} and the corresponding category over the skew group algebra \QTR{sl}{C}% [X]\ast G. We obtain a generalization of known results for $n=2$ and $G$ a finite subgroup of $Sl(2,C)$. In the last part of the paper we extend the results for the polynomial algebra $C[X]$ to the homogenized Weyl algebra $B_{n}$

Skew Group Algebras and their Yoneda Algebras

Skew group algebras appear in connection with the study of singularities [1], [2]. It was proved in [4], [6], [10] the preprojective algebra of an Euclidean diagram is Morita equivalent to a skew group algebra of a polynomial algebra. In [7] we investigated the Yoneda algebra of a selfinjective Koszul algebra and proved they have properties analogous to the commutative regular algebras, we call such algebras generalized Auslander regular. The aim of the paper is to prove that given a positively graded locally finite K-algebra &#923; = &#8721;&#943;&#8805;0 &#923;&#943; and a finite grading preserving group G of automorphisms of &#923;, with characteristic K not dividing the order of G, then G acts naturally on the Yoneda algebra &#915; =&#8853;&#954;&#8805;0&#12288;Extk&#923;(&#923;0,&#923;0) and the skew group algebra &#915;*G is isomorphic to the Yoneda algebra &#923;*G = &#8853;&#954;&#8805;0 Ext&#954;&#923;*G(&#923;0*G,&#923;0*G). As an application we prove &#923; is generalized Auslander regular if and only if &#923;*G is generalized Auslander regular and &#923; is Koszul if and only if &#923;*G is so.</p

«Workers, do not vote!». CNT and Spanish Popular Front in the 1936 general elections

Este artículo pretende aclarar la postura de la CNT y la FAI ante las elecciones generales de 1936. Se analiza cómo tradujeron los propagandistas de ambas organizaciones las ponencias electorales aprobadas en sus Plenos durante la campaña electoral. La comparación con la propaganda anarcosindicalista de noviembre de 1933 y el análisis de las concepciones dispares que la CNT y las izquierdas coaligadas en el Frente Popular mantenían sobre la amnistía y el peligro fascista, cuestionan que en 1936 se produjera una convergencia de intereses entre ambas y, por tanto, un relajamiento en las posiciones apolíticas y antielectorales de aquélla.This article aims to explain the position of CNT and FAI in the general elections of 1936. It analyzes how propagandists of both organizations understood the instructions, approved in their plenary meetings, during the election campaign. A comparison with anarcho-syndical propaganda of November 1933, as well as an analysis of the different points of view that CNT and the leftist coalition called Popular Front had about amnesty and fascist danger, challenge the idea that they shared similar interests in 1936 and that laxity in the anarchist position against politics and elections took place therein

Estructura de capital, concentración de propiedad y política de dividendos como factores determinantes de problemas de agencia en empresas chilenas

The objective of this paper is to analyze the capital structure, the concentration of property and the policy of dividends as determinants of the problems of agency in Chilean companies. As a measure of agency costs, the asset turnover ratio was used as a benchmark for management efficiency in the use of the company's assets, which is an inverse measure of agency costs. The results show that a higher level of indebtedness seems to favor the discretional behavior of managers. However, there is also evidence that when the debt is a short-term debt, the divergence of interest decreases between shareholders and managers. The concentration of property on the other hand has a non-linear effect on the costs of agency, which means that, first, it acts as a mechanism to attenuate managerial discretion, but when it reaches a certain level, an effect of expropriation of major shareholders over minor shareholders seems to be produced. In relation to the dividend policy, a positive relationship is observed with efficiency in the use of assets, mainly in the presence of high growth opportunities.El objetivo de este trabajo es analizar la estructura de capital, la concentración de propiedad y la política de dividendos como factores determinantes de los problemas de agencia en las empresas chilenas. Como medida de costos de agencia se utilizó el ratio de rotación de activos como referencia de la eficiencia directiva en el aprovechamiento de los activos de la empresa, lo cual constituye una medida inversa de costos de agencia. Los resultados muestran que un mayor nivel de endeudamiento pareciera favorecer el comportamiento discrecional por parte de los directivos. Sin embargo, también hay evidencia de que cuando la deuda es a corto plazo la divergencia de intereses disminuye entre accionistas y directivos. La concentración de propiedad por su parte arroja un efecto no lineal sobre los costos de agencia, es decir, en primera instancia actúa como un mecanismo para atenuar la discrecionalidad directiva pero al llegar a un cierto nivel, pareciera producirse un efecto de expropiación de los accionistas mayoritarios sobre los minoritarios. En relación a la política de dividendos, se observa una relación positiva con la eficiencia en la utilización de los activos principalmente en presencia de altas oportunidades de crecimiento