Fermion production during preheating after hybrid inflation

At the end of inflation, the coherent oscillations of the inflaton field may resonantly amplify the long wavelength modes of both bosons and fermions coupled to it. We study the resonant production of both kinds of particles during preheating in a model of hybrid inflation. The coherent time evolution of the inflaton and the Higgs fields after inflation induce a very different production of fermions depending on whether they are coupled to the Higgs or to the inflaton. For reasonable values of the model parameters, the fermion production through parametric resonance can be very efficient. We study the relative growth of the fermion and boson energy densities during preheating in hybrid models. During the initial stage of preheating, fermion production dominates the relative energy density, while the exponential growth of bosonic modes soon takes over.Comment: 20 pages, 14 figures, uses epsfig and JHEP macros (included

On the Determination of Leptonic CP Violation and Neutrino Mass Ordering in Presence of Non-Standard Interactions: Present Status

We perform a global analysis of neutrino data in the framework of three massive neutrinos with non-standard neutrino interactions which affect their evolution in the matter background. We focus on the effect of NSI in the present observables sensitive to leptonic CP violation and to the mass ordering. We consider complex neutral current neutrino interactions with quarks whose lepton-flavor structure is independent of the quark type. We quantify the status of the "hints" for CP violation, the mass-ordering and non-maximality of $\theta_{23}$ in these scenarios. We also present a parametrization-invariant formalism for leptonic CP violation in presence of a generalized matter potential induced by NSI.Comment: 24 pages, 4 figure

More than two are a crowd. Different paths to effectiveness in dyadic and multi-party joint ventures

Using data from 87 joint venture (JV) experiences, we compared the effectiveness of dyadic and multi-party JVs. We show that dyadic JVs are more effective than multi-party ones, and that the conditions resulting in an enhanced effectiveness differ for the two groups: while relational embeddedness significantly influences the effectiveness of dyadic JVs, monitoring mechanisms are pivotal in the case of multi-party JVs.joint venture;

Cooperation, competition and the longevity of stakes in joint ventures: A value creation approach

This research used a transaction value perspective (Zajac and Olsen, 1993; Madhok and Tallman, 1998) to examine the impact of competitive and cooperative forces on joint venture (JV) duration. We argue that some factors increasing the management cost of the JV may also increase its value potential. Such factors include whether the partners are direct competitors, and whether their nationality is the same. Findings from a survey study provided support for all of our hypothesesCooperation; joint ventures; competition;

La musealización del patrimonio natural para su conservación, Museo Luis Mario Schneider, Malinalco, México

El presente artículo desarrolla la importancia del patrimonio natural mediante el trabajo realizado por la Universidad Autónoma del Estado de México, la cual comprende que la educación forma parte esencial en la preservación del entorno natural; es por esta razón que contribuye de manera activa en impulsar la responsabilidad social, al promover el cuidado de éste y otros patrimonios mediante la musealización. El texto resalta el trabajo realizado en el Museo Universitario Dr. Luis Mario Schneider, ubicado en Malinalco, Estado de México, en donde se mencionan aspectos importantes como su arquitectura, guión museográfico, museografía, exposiciones temporales y las diversas áreas que conforman un diseño integral, con el objetivo de considerar este museo como un ejemplo en la generación de nuevos espacios culturales que favorezcan el cuidado del medioambiente. Cabe mencionar el esfuerzo realizado en el proceso de diseño, así como la labor que se realiza cada día para transmitir con calidez el mensaje del museo mediante las visitas guiadas. Lo anterior ha dado como resultado una aceptación que se evidencia en los comentarios del cuaderno dispuesto a los visitantes para compartir sus opiniones sobre el museo, así como en la donación de piezas por parte de los pobladores. El libro de Registro ubicado en el acceso del inmueble, indica un promedio de 27 000 visitantes por año