The impact of the air-fluorescence yield on the reconstructed shower parameters of ultra-high energy cosmic rays

An accurate knowledge of the fluorescence yield and its dependence on atmospheric properties such as pressure, temperature or humidity is essential to obtain a reliable measurement of the primary energy of cosmic rays in experiments using the fluorescence technique. In this work, several sets of fluorescence yield data (i.e. absolute value and quenching parameters) are described and compared. A simple procedure to study the effect of the assumed fluorescence yield on the reconstructed shower parameters (energy and shower maximum depth) as a function of the primary features has been developed. As an application, the effect of water vapor and temperature dependence of the collisional cross section on the fluorescence yield and its impact on the reconstruction of primary energy and shower maximum depth has been studied.Comment: Accepted in Astroparticle Physic

The geometry of modified Riemannian extensions

We show that every paracomplex space form is locally isometric to a modified Riemannian extension and give necessary and sufficient conditions so that a modified Riemannian extension is Einstein. We exhibit Riemannian extension Osserman manifolds of signature (3,3) whose Jacobi operators have non-trivial Jordan normal form and which are not nilpotent. We present new four dimensional results in Osserman geometry

Los Invisibles

Examining the social, medical and cultural history of male homosexuality in Spain, this book looks at it from the time homosexuality came to be an issue of medical, legal and cultural concern. Research into homosexuality in Spain is in its infancy. The last ten or fifteen years have seen a proliferation of studies on gender in Spain but much of this work has concentrated on women's history, literature and femininity. In contrast to existing research which concentrates on literature and literary figures, "Los Invisibles" focuses on the change in cultural representation of same-sex activity of through medicalisation, social and political anxieties about race and the late emergence of homosexual sub-cultures in the last quarter of the twentieth century. As such, this book constitutes an analysis of discourses and ideas from a social history and medical history position. Much of the research for the book was supported by a grant from the Wellcome Trust to research the medicalisation of homosexuality in Spain

Stanilov-Tsankov-Videv Theory

We survey some recent results concerning Stanilov-Tsankov-Videv theory, conformal Osserman geometry, and Walker geometry which relate algebraic properties of the curvature operator to the underlying geometry of the manifold.Comment: This is a contribution to the Proceedings of the 2007 Midwest Geometry Conference in honor of Thomas P. Branson, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA