On quantum and parallel transport in a Hilbert bundle over spacetime

We study the Hilbert bundle description of stochastic quantum mechanics in curved spacetime developed by Prugove\v{c}ki, which gives a powerful new framework for exploring the quantum mechanical propagation of states in curved spacetime. We concentrate on the quantum transport law in the bundle, specifically on the information which can be obtained from the flat space limit. We give a detailed proof that quantum transport coincides with parallel transport in the bundle in this limit, confirming statements of Prugove\v{c}ki. We furthermore show that the quantum-geometric propagator in curved spacetime proposed by Prugove\v{c}ki, yielding a Feynman path integral-like formula involving integrations over intermediate phase space variables, is Poincar\'e gauge covariant (i.e.$\!$ is gauge invariant except for transformations at the endpoints of the path) provided the integration measure is interpreted as a ``contact point measure'' in the soldered stochastic phase space bundle raised over curved spacetime.Comment: 25 pages, Plain TeX, harvmac/lanlma

Mass-Generation by Weyl-Symmetry Breaking

A massless electroweak theory for leptons is formulated in a Weyl space, W_4, yielding a Weyl invariant gauge dynamics allowing for conformal rescalings of the metric and all fields with nonvanishing Weyl weight together with the corresponding transformations of the Weyl vector fields representing the D(1) or dilatation gauge fields. To study the appearance of nonzero masses this theory is explicitly broken by a term in the Lagrangean involving the curvature scalar R of the W_4 and a mass term for the scalar field. Thereby also the gauge fields as well as the charged fermion field acquire a mass as in the standard electroweak theory. The symmetry breaking is governed by the relation D Phi^2=0, where Phi is the modulus of the scalar field and D denotes the Weyl-covariant derivative. This true symmetry reduction, establishing a scale of length in the theory, is compared to the so-called spontanous symmetry breaking in the standard electroweak theory which is, actually, the choice of a particular (nonlinear) gauge obtained by adopting an origin in the coset space representing the scalar field which is invariant under the electromagnetic gauge group. Particular attention is devoted to the appearance of Einstein's equations for the metric after the Weyl-symmetry breaking yielding a pseudo-Riemannian space V_4 from a W_4 and a scalar field with a constant modulus which in turn affects Einstein's gravitational constant in a manner comparable to the Brans-Dicke theory.Comment: LaTex, revtex, 36 page

The Impact of New Product Announcements on Quick Service Restaurant Companies’ Stock Returns

This study seeks to answer two main questions: 1) Do product announcements impact quick service restaurant stock returns? 2) Do economic conditions impact the degree which product announcements impact quick service restaurant stock returns? 159 total product announcements were collected for 6 quick service companies: McDonald’s Corp., YUM! Brands Inc., The Wendy’s Co., AFC Enterprises Inc., Jack in the Box Inc., and Sonic Corp. 84 of these announcements were from 2005-2007 (Labeled “Pre-Recession”), and 75 were from 2009-2011 (Labeled “Post-Recession”). Using historical stock price data, an analysis of the overall trends of the mean-adjusted excess returns was conducted to determine whether or not product announcements impact the stock returns. Further analysis was conducted to determine whether the “Pre-Recession” results had different results from the “Post-Recession” results, demonstrating a difference between two different economic periods. The results showed that on average, the day following the product announcement had negative excess returns. In addition, there was a noticeable difference between “Pre-Recession” and “Post-Recession” post-announcement returns behavior. “Pre-Recession” results, on average, had positive excess returns in the 10 days following the product announcement, while “Post-Recession” results had negative excess returns in the 10 days following the product announcement

Improved ferrous shielding for flat cables

To improve shielding of flat multicore cables, a thin, seamless ferrous shield around all cores optimizes low frequency magnetic shielding. Such shielding is covered with an ultrathin seamless coat of highly conductive nonferrous material

Multiple imputation of missing values in the wave 2007 of the IAB Establishment Panel

"The basic concept of multiple imputation is straightforward and easy to understand, but the application to real data imposes many implementation problems. To define useful imputation models for a dataset that consists of categorical and of continuous variables with distributions that are anything but normal, contains skip patterns and all sorts of logical constraints is a challenging task. In this paper, we review different approaches to handle these problems and illustrate their successful implementation for a complex imputation project at the German Institute for Employment Research (IAB): The imputation of missing values in one wave of the IAB Establishment Panel." (Author's abstract, IAB-Doku) ((en))Missing Data-Technik, Datenqualität, IAB-Betriebspanel, statistische Methode, Imputationsverfahren

Replicating the Synthetic LBD with German Establishment Data

One major criticism against the use of synthetic data has been that the efforts necessary to generate useful synthetic data are so intense that many statistical agencies cannot afford them. However, we argue in this paper that the field is still evolving and many lessons that have been learned in the early years of synthetic data generation can now be used in the development of new synthetic data products, considerably reducing the required investments. We evaluate whether synthetic data algorithms that have been developed in the U.S. to generate a synthetic version of the Longitudinal Business Database (LBD) can easily be transferred to generate a similar data product for other countries. We construct a German data product with information comparable to the LBD - the German Longitudinal Business Database (GLBD) - that is generated from different administrative sources at the Institute for Employment Research, Germany. In a second stage, the algorithms developed for the synthesis of the LBD will be applied to the GLBD. Extensive evaluations will illustrate whether the algorithms provide useful synthetic data without further adjustment. The ultimate goal of the project is to provide access to multiple synthetic datasets similar to the SynLBD at Cornell to enable comparative studies between countries. The Synthetic GLBD is a first step towards that goal

Exotic mitotic mechanisms

The emergence of eukaryotes around two billion years ago provided new challenges for the chromosome segregation machineries: the physical separation of multiple large and linear chromosomes from the microtubule-organizing centres by the nuclear envelope. In this review, we set out the diverse solutions that eukaryotic cells use to solve this problem, and show how stepping away from ‘mainstream’ mitosis can teach us much about the mechanisms and mechanics that can drive chromosome segregation. We discuss the evidence for a close functional and physical relationship between membranes, nuclear pores and kinetochores in generating the forces necessary for chromosome segregation during mitosis