Spherically symmetric solutions of a boundary value problem for monopoles

In this paper we study spherically symmetric monopoles, which are critical points for the Yang-Mills-Higgs functional over a disk in 3 dimensions, with prescribed degree and covariant constant at the boundary. This is a 3-dimensional gauge-theory generalization of the Ginzburg-Landau model in 2 dimensions.Comment: 15 pages, 2 figures, LaTe

Dynamics in an OLG model with non-separable preferences

This paper presents sufficient conditions for existence and uniqueness of a steady state equilibrium in an OLG model with non separable preferences and analyzes the implications of such assumption for the local stability of the steady state equilibrium. The conditions for a stable solution are derived under the assumption that habits are transmitted both across and within generations. Under this assumption, monotonic convergence to the steady state is not always assured. Both competitive and optimal equilibrium may display explosive dynamics

{\it Ab--initio} finite temperature excitons

The coupling with the lattice vibrations is shown to drastically modify the state--of--the--art picture of the excitonic states based on a frozen atom approximation. The zero--point vibrations renormalize the bare energies and optical strengths. Excitons acquire a non--radiative lifetime that decreases with increasing temperature. The optical brightness and efficiency turn out to be strongly temperature dependent such as to induce bright to dark (and vice versa) transitions. The finite temperature experimental optical absorption spectra of bulk Si and hexagonal BN are successfully explained without using any external parameter.Comment: 4 pages, 2 figure

A note on the power of panel conitegration tests - An application to health care expenditure and GDP

This paper enlarges on Gutierrez's (2003) results on the power of panel cointegration tests. By a comparison of power of panel cointegration tests, we show how the choice of most powerful test depends on the values of the sample statistics. Country - by - country and panel stationarity and cointegration tests are performed on a panel of 20 OECD countries over the period 1971 - 2004. Residual - based tests and a cointegration rank test in the system of health care expenditure and GDP are used to test cointegration. Asymptotic normal distribution of these tests allows a straightforward comparison: for some values of the sample statistics, residual - based and rank tests are not directly comparable as the power of the residual - based tests oscillates; for other values of the sample statistics, the rank test is more powerful than the residual - based tests. This suggests that a clear-cut conclusion on the most powerful test cannot be reached a priori

A content analysis of Chicago Cubs and White Sox local news coverage during the 2004 and 2008 major league baseball seasons

This research paper explored how the media presented information about the Chicago Cubs and White Sox during the 2004 and 2008 seasons. This was accomplished through content analysis from sports sections of both, The Chicago Tribune and Chicago Sun Times, totaling 167 articles containing 2,777 paragraphs. This analysis measured quantity and tone of news coverage with cross-comparisons between two teams, two years and two news sources. Each paragraph was assigned to one of the teams and categorized into a pre-determined coding group. These coding groups were classified as positive, negative, or neutral in tone. This study sought to identify whether significant agenda-setting or framing differences existed between the Chicago Cubs and Chicago White Sox and how this differences could have impact on object salience. The theories of agenda-setting and framing will provide insight into the decision making process of sportswriters as to: how much information of each subject is being presented (quantity), and how the story is presenting the subject (tone). The Cubs received a slightly higher amount of coverage than the White Sox for the entirety of the study. However, as total coverage decreased, from 2004 to 2008, the majority of which was in coverage for the White Sox. Thus, suggesting an agenda-setting function in this particular area of the study. Both the White Sox and Cubs received more neutral coverage, than positive or neutral frames. The remained constant to the study, with the exception of the Cubs in the year 2008, where they received a significant amount of positive coverage as opposed to their 2004 season. This paper sought the theories of framing and agendasetting beyond their popular reach in the political world. by applying them to sports writing, a previously untapped discipline.Department of JournalismThesis (M.A.

An Application of Constant Market Share Analysis for the Study of Firm Profitability

We propose a new decomposition of the return on investment (ROI) – the main accounting measure of firm profitability – to evaluate the contributions of its three components: the return on sales (ROS), the utilization (rotation) of working capital (RCC), and the utilization (rotation) of fixed capital (RCF). By using this decomposition we develop an original variant of the constant market share (CMS) analysis specifically for comparisons of firm average profitability between countries and over time. The proposed CMS methodology allows us to separate the variation of the average ROI over time (or its difference between two countries) in three components: a competitiveness effect – the difference of average ROI assuming the same reference structure for the two terms of comparison – a structure effect – the result of the difference in the internal articulation of the ROI by sector and by size structure within the two terms of comparison – and an adaptation effect, which takes into account the synergies between the two previous components. The decomposition of the ROI in the product of the three terms, ROS, RCC and RCF, plays an original role in the interpretation of the competitiveness effect. An application of the proposed methodology is carried out for the comparison of the average ROI in the industrial sector among Germany, Italy and France and over the years 2006-2008.constant market share analysis; return on investment; return on sales; rotation of invested capital; comparison over time; comparison over countries

Stable producer co-operatives in competitive markets

An argument often adopted to explain the relatively scarce presence of Producer Co-operatives (PCs) in Western capitalist economies is the instability that may affect this type of firm during the positive phases of the business cycle. In a nutshell the argument is that in profitable industries PCs can have an incentive to hire fixed-wage workers to replace the relatively more expensive firm's members. The paper shows that this phenomenon can fail to hold in very competitive and low barrier-to-entry markets in which, potentially, dismissed members have a chance to set up new firms. Furthermore, since some basic results on PC's stability are due to the assumption of an exogenous equilibrium wage as opposed to an endogenous PC's payoff, the paper attempts to remove this assumption. Two main insights are thus provided. Firstly, that workers possess an incentive to set up PCs only under specific circumstances. Secondly, that once PCs enter a market, conditions exist under which they are stable against the temptation to dismiss members to hire fixed-wage workers.Producer Co-operatives, Wages, Self-employment