Segal objects and the Grothendieck construction

We discuss right fibrations in the $\infty$-categorical context of Segal objects in a category V and prove some basic results about these.Comment: 26 page

Possible scenario for MaVaN's as the only neutrino flavor conversion mechanism in the Sun

Mass Varying neutrino mechanisms were proposed to link the neutrino mass scale with dark energy, addressing the coincidence problem. In some scenarios this mass can present a dependence on the baryonic density felt by neutrinos, creating an effective neutrino mass that depends both on the neutrino and baryonic densities. In this article we investigate the possibility that a neutrino effective mass is the only flavour conversion mechanism acting in neutrino oscillation experiments. We present a parameterization on the environmental effects on neutrino mass that produces the right flavour conversion probabilities for solar and terrestrial neutrinos experiments.Comment: 12 pages, 4 figure

Global supply chains of high value low volume products

Imperial Users onl

Instalación eléctrica y contra incendios de una nave industrial de mecanizado de metales

El presente proyecto de final de grado, tiene como finalidad el diseño, cálculo y dimensionamiento de las instalaciones eléctrica y contra incendios para una nave industrial dedicada al mecanizado de todo tipo de metales. La nave está situada en el municipio de Sant Adrià de Besós y consta de dos plantas, planta baja y planta primera. El proyecto incluye toda la documentación necesaria para su realización teniendo en cuenta las características del edificio, las necesidades mínimas para el tipo de actividad desarrollada y cumpliendo en todo momento las normativas vigentes en cada apartado. El proyecto consta de una memoria donde se describen las diferentes instalaciones aportando la documentación necesaria y las soluciones adoptadas justificadas mediante los cálculos pertinentes. Complementándolo con diversos planos de situación de elementos a instalar, así como esquemas unifilares de dichas instalaciones. También se ha realizado una valoración económica, tanto de materiales como de mano de obra teniendo en cuenta el beneficio industrial

Socio-Economic Status, HIV/AIDS Knowledge and Stigma, and Sexual Behavior in India

Using data from the National Family Health Surveys (NFHS-3), this paper analyzes the socioeconomic correlates of sexual behavior, HIV/AIDS knowledge and stigma in India. The main findings are that, overall, the Indian population is faithful and abstains from sex with very small variations across socioeconomic classes. However, given the large size of the population, there is still room for some concern as condom use is low, knowledge about the disease is poor, and stigma is high; especially with respect to less educated, poorer, single males and women in general. Obvious policy recommendations are; therefore, to increase condom distribution and awareness, increase very heavily HIV/AIDS basic education, and promote women empowerment with respect to sexual choices.HIV/AIDS, Condom, Stigma, India

Growth, Fiscal Policy and the Informal Sector in a Small Open Economy

We discuss the implications of informality on growth and fiscal policy by considering an informal sector based on low tech firms, in an open economy model of endogenous growth, where labour supply is elastic and increasing returns arise from public spending. We allow for both labour and capital to allocate between sectors and examine the dynamic and policy issues that arise in an economy, where long run outcomes are still dominated by formal activities, but long macroeconomic transitions arise as a result of informal microeconomic activities, which take advantage of both government taxation and limited fiscalization.Endogenous Growth Theory; Optimal Fiscal Policy; Informal Sector; Public Capital

Self-Enforcing Climate Change Treaties: A Generalized Differential Game Approach with Applications

Based on recent proposals on non cooperative dynamic games for analysing climate negotiation outcomes, such as Dutta and Radner (2004, 2006a), we generalize a specific framework for modelling differential games of this type and describe the set of conditions for the existence of closed loop dynamics and its relation to adaptive evolutionary dynamics. We then show that the Dutta and Radner (2004, 2006a) discrete time dynamic setup is a specific case of that generalization and describe the dynamics both analytically and numerically for closed loop feedback and perfect state patterns. Our discussion is completed with the introduction of a cooperative differential framework for welfare analysis purposes, within our non cooperative proposal for climate negotiations.Differential Game Theory, Environmental Economics, Evolutionary Dynamics, Climate Change Treaties

Calculating Welfare Costs of Inflation in a Search Model with Preference Heterogeneity: A Calibration Exercise

Using U.S. cross-sectional data, this paper calculates the welfare cost of a 10% inflation for different individuals and finds that the difference in cost between the poorest 10%, measured by their expenditure share on cash goods, and the richest 10% is in the order of 176%. That is, a poor person is on average willing to forgive 176% more of their total consumption in order to have inflation reduced from 10% to 0. In absolute terms this represents a cost of 2.687% of consumption for the poorest and 0.974% for the richest. I accomplish this by introducing preference heterogeneity in a monetary search model first developed by Lagos and Wright (2005), and calibrate the model to match the expenditure share on cash goods and total expenditures for each individual type using data from the Consumer Expenditure Survey (CEX) for the second quarter of 1996. I also show that this welfare difference increases to 210% (10.522% for the poorest 10% and 3.401% for the richest 10%) whenever frictions in the use of money are imposed (holdup problem). The ability to explicitly model these frictions is the advantage of using this model. Hence, inflation in this framework, as other studies have shown, acts as a regressive consumption tax; and this regressiveness is augmented with the holdup problem.Inflation, welfare, search, holdup