Quantum Mechanics was first conceived at the turn of the twentieth century, and since has shook the foundations of modern physics. It is a radically different viewpoint from classical physics, which works on the macroscopic scale, in contrast to quantum mechanics' microscopic domain. Though at first it was heavily debated by members of the scientific communit, it is and has been both theoretically and experimentally verified by the likes of Einstein, Heisenberg, Shr\"{o}dinger, to name but a few. This being said, it is still an incomplete theory, and has yet not been concretely proved, despite strong experimental evidence for its truth. The aim of this report is to introduce the field of quantum mechanics, and to investigate the notions of conservation/symmetry, familiar from classical mechanics. The transformations we consider here are parity/space-inversion, lattice translation and time reversal. We will build a knowledge base by analysng the operators that represent these transformation within a quantum mechanical framework. This paper is presented for an audience that has completed a mathematics degree course up to and including second year. The specific feilds we draw upon include differential equations (MA1OD1, MA2OD2, MA2PD1), linear algebra (MA2LIN), and dynamics (MA2DY). These modules are assumed to be prior knowledge. The main sources of information for this project are:
An Introduction To Quantum Mechanics, D.J. Griffiths (1995), Second edition, Pearson Education ltd., 2005
Modern Quantum Mechanics, J.J. Sakurai (1994), First edition, Addison-Wesley Publishing Company inc. 1994
which are referenced throughout. For specific pages, see the bibliography, which is found in section 6.
Introducción: Este manual ha sido realizado para dar una pequeña introducción de como funciona esta maravillosa herramienta; se la da un uso muy practico para la planeación de proyectos y con la asignación de recursos hace que mejore mucho. Muy practica con las diversas graficas que se muestran se entiende mas el desarrollo del proyecto con las catividades que se llevaran acabo dentro de la planeación.
This paper explores the relationship between ethnic fractionalization and social capital between 1990-2005. First, using data from 1990, 1997 and 2005 we test for time differences in the impact of ethnic fractionalization on social capital. Subsequently, we examine U.S. data for evidence consistent with the proposed outcomes in the conflict, contact, or hunker-down theses discussed in Putnam (2007). Putnam (2007) examines what happens to “trust" or “social capital" when individuals of different ethnicity are introduced into social, political and/or economic groups over time. Using an instrumental variable (IV) estimator, we find little evidence of heterogeneity in the impact of ethnic fractionalization on social capital over our period of analysis. In addition, using both fixed effect and IV estimators, we reject the contact hypothesis, but find evidence consistent with the outcomes predicted in both the conflict hypothesis and Putnam’s hunker-down hypothesis, in inter-ethnic relations. Due to data limitations, we are unable to test directly which of these two thesis are more relevant for the U.S experience. However, we provide suggestive evidence in support of the conflict hypothesis over the hunker-down hypothesis. Our results suggest that between 1990-2005, as communities in the U.S became more diverse, there was a tendency for social capital to decline.