On the derivatives of generalized Gegenbauer polynomials

We prove some new formulae for the derivatives of the generalized Gegenbauer polynomials associated to the Lie algebra $A_2$.Comment: 3 pages, no figures; submitted to Theor. Math. Phy

On the spectrum of nonrelativistic AdS/CFT

We develop a Hamiltonian picture for a family of models of nonrelativistic AdS/CFT duality. The Schrodinger group is realized via the conformal quantum mechanics of De Alfaro, Fubini and Furlan in the holographic direction. We show that most physical requirements, including the introduction of harmonic traps, can be realized with exact AdS metrics, but without any need for exotic matter sectors in the bulk dynamics. This Hamiltonian picture can be used to compare directly with many-body spectra of fermions at unitarity on harmonic traps, thereby providing a direct physical interpretation of the holographic radial coordinate for these systems. Finally, we add some speculations on the dynamical generation of mass gaps in the AdS description, the resulting quasiparticle spectra, and the analog of `deconfining' phase transitions that may occur.Comment: 20 pages and 1 figure; typos corrected, references added; references added, minor changes matching published versio

Contractors Perspective on the Selection of Innovative Sustainable Technologies for Achieving Zero Carbon Retail Buildings

The use of innovative sustainable technologies (IST) has been regarded as an effective approach to enhancing energy efficiency and reducing carbon emissions of buildings. However, contractors face significant challenges in the selection of IST. The reported challenges in the literature include: lack of skills and knowledge, uncertainties, risks and the rapid development of a large number of technological alternatives and decision criteria. The selection process emerges as a multi-attribute, value-based task that includes both qualitative and quantitative factors, which are often assessed with imprecise data and human judgments. This paper aims to establish the decision criteria for the selection of IST for achieving low carbon existing retail buildings with a focus on the main contractor’s perspective. The arguments are informed by the combination of literature review and an in-depth case study with a UK leading contractor. Five broad decision criteria are identified systematically drawing on the contractor’s practice. The established criteria are weighted and ranked using the analytic hierarchy process and expert opinions; with ‘margin opportunity’ being the most important, followed by ‘repeat business’, ‘investment costs’, ‘differentiation’ and then ‘transferability’. The findings should facilitate the integration of various facets of the selection process and stimulate contractors to use IST

Explicit computations of low lying eigenfunctions for the quantum trigonometric Calogero-Sutherland model related to the exceptional algebra E7

In the previous paper math-ph/0507015 we have studied the characters and Clebsch-Gordan series for the exceptional Lie algebra E7 by relating them to the quantum trigonometric Calogero-Sutherland Hamiltonian with coupling constant K=1. Now we extend that approach to the case of general K

On forecasting daily stock volatility: the role of intraday information and market conditions

Several recent studies advocate the use of nonparametric estimators of daily price vari- ability that exploit intraday information. This paper compares four such estimators, realised volatility, realised range, realised power variation and realised bipower variation, by examining their in-sample distributional properties and out-of-sample forecast ranking when the object of interest is the conventional conditional variance. The analysis is based on a 7-year sample of transaction prices for 14 NYSE stocks. The forecast race is conducted in a GARCH framework and relies on several loss functions. The realized range fares relatively well in the in-sample .t analysis, for instance, regarding the extent to which it brings normality in returns. However, overall the realised power variation provides the most accurate 1-day-ahead forecasts. Fore- cast combination of all four intraday measures produces the smallest forecast errors in about half of the sampled stocks. A market conditions analysis reveals that the additional use of intraday data on day t .. 1 to forecast volatility on day t is most advantageous when day t is a low volume or an up-market day. The results have implications for value-at-risk analysis.

Sieve bootstrap t-tests on long-run average parameters

Panel estimators can provide consistent measures of a long-run average parameter even if the individual regressions are spurious. However, the t-test on this parameter is fraught with problems because the limit distribution of the test statistic is non-standard and rather complicated, particularly in panels with mixed (non-)stationary errors. A sieve bootstrap framework is suggested to approximate the distribution of the t-statistic. An extensive Monte Carlo study demonstrates that the bootstrap is quite useful in this context

La coerción sexual en las relaciones de los y las adolescentes y jóvenes: naturaleza del problema y estrategias de intervención

La coerción sexual entre los adolescentes, se ha convertido en un importante problema en nuestra sociedad, tanto por su amplitud como por las consecuencias que a menudo de ella se derivan. Sin duda, como profesionales de la Psicología y la Educación hemos de intentar ofrecer respuestas eficaces a esta situación, y una de las prioritarias es el desarrollo de programas de prevención que reduzcan su incidencia. En este trabajo nos acercamos a la problemática de la coerción sexual en la adolescencia con el objeto de contribuir a su prevención. De este modo analizamos los factores de riesgo asociados, tanto a la perpetración de la coerción, como a la victimización, para posteriormente plantear, en función de ello, cuáles podrían ser los aspectos más relevantes a trabajar en un programa de prevención en el contexto educativo.Sexual coercion among adolescents has becoming an important problem in our society, because of its high prevalence, as well as the negative consequences that this phenomenon can cause; for this reason, psychologists and educators must try to offer effective responses to this situation. In this sense, one of the most important objectives in this field is to develop preventive programs to decrease its incidence. In this paper, we seek to approach to the understanding of sexual coercion among youths in order to contribute to its prevention. With this aim, in this work we analyze some risk factors associated to the perpetration of sexual coercion as well as episodes of sexual victimization, and before that we speak about key points that should be taken into account to design preventive programs for educational contexts