Curvature and topological effects on dynamical symmetry breaking in a four- and eight-fermion interaction model

A dynamical mechanism for symmetry breaking is investigated under the circumstances with the finite curvature, finite size and non-trivial topology. A four- and eight-fermion interaction model is considered as a prototype model which induces symmetry breaking at GUT era. Evaluating the effective potential in the leading order of the 1/N-expansion by using the dimensional regularization, we explicitly calculate the phase boundary which divides the symmetric and the broken phase in a weakly curved space-time and a flat space-time with non-trivial topology, $R^{D-1} \otimes S^1$.Comment: 20 pages, 21 figure

Stringy effect of the holographic correspondence for Dp-brane backgrounds

Based on the holographic conjecture for superstrings on Dp-brane backgrounds and the dual (p+1)-dimensional gauge theory ($0\le p\le 4$) given in hep-th/0308024 and hep-th/0405203, we continue the study of superstring amplitudes including string higher modes ($n\ne 0$). We give a prediction to the two-point functions of operators with large R-charge J. The effect of stringy modes do not appear as the form of anomalous dimensions except for p=3. Instead, it gives non-trivial correction to the two-point functions for supergravity modes. For p=4, the scalar two-point functions for any n behave like free fields of the effective dimension d_{eff}=6 in the infra-red limit.Comment: 23 pages, typos correcte

HCN to HCO^+ Millimeter Line Diagnostics of AGN Molecular Torus I : Radiative Transfer Modeling

We explore millimeter line diagnostics of an obscuring molecular torus modeled by a hydrodynamic simulation with three-dimensional nonLTE radiative transfer calculations. Based on the results of high-resolution hydrodynamic simulation of the molecular torus around an AGN, we calculate intensities of HCN and HCO^{+} rotational lines as two representative high density tracers. The three-dimensional radiative transfer calculations shed light on a complicated excitation state in the inhomogeneous torus, even though a spatially uniform chemical structure is assumed. Our results suggest that HCN must be much more abundant than HCO^{+} in order to obtain a high ratio ($R_{HCN/HCO+}\sim 2$) observed in some of the nearby galaxies. There is a remarkable dispersion in the relation between integrated intensity and column density, indicative of possible shortcomings of HCN(1-0) and HCO^{+}(1-0) lines as high density tracers. The internal structures of the inhomogeneous molecular torus down to subparsec scale in external galaxies will be revealed by the forthcoming Atacama Large Millimeter/submillimeter Array (ALMA). The three-dimensional radiative transfer calculations of molecular lines with high-resolution hydrodynamic simulation prove to be a powerful tool to provide a physical basis for molecular line diagnostics of the central regions of external galaxies.Comment: 29 pages, 13 figures, Accepted for publication in ApJ, For high resolution figures see http://alma.mtk.nao.ac.jp/~masako/MS72533v2.pd

Developing In-House Careers and Retaining Management Talent: What Hospitality Professionals Want from Their Jobs

One of the primary challenges the hospitality industry faces continues to be high levels of turnover. In this study, the authors examine turnover intentions of one of the most critical groups of employees: management staff. Using a sample of Cornell University School of Hotel Administration graduates from 1987 through 2002, the authors identify the job features that enhance managers\u27 commitment levels to their organizations and to the overall industry, as well as reduce their likelihood of leaving both. Results suggest that hospitality managers are taking charge of their careers. They are looking for challenging jobs that offer growth opportunities, as well as competent leadership and fair compensation. To the degree these job features are in place, hospitality managers\u27 commitment levels will rise. Managers\u27 commitment to performing challenging work especially reduces their likelihood of leaving their companies and the industry

GMs’ Responses to the Events of September 11, 2001

Hotel managers’ actions after 9–11 included modifying marketing activities, reducing employees’ hours, and either postponing capital improvements (for lack of cash flow) or accelerating planned upgrades while business is slow

Drive level dependency in quartz resonators

AbstractCommon piezoelectric resonators such as quartz resonators have a very high Q and ultra stable resonant frequency. However, due to small material nonlinearities in the quartz crystal, the resonator is drive level dependent, that is, the resonator level of activity and its frequency are dependent on the driving, or excitation, voltage. The size of these resonators will be reduced to one fourth of their current sizes in the next few years, but the electrical power which is applied will not be reduced as much. Hence, the applied power to resonator size ratio will be larger, and the drive level dependency may play a role in the resonator designs.We study this phenomenon using the Lagrangian nonlinear stress equations of motion and Piola–Kirchhoff stress tensor of the second kind. Solutions are obtained using COMSOL for the AT-cut, BT-cut, SC-cut and other doubly rotated cut quartz resonators and the results compared well with experimental data. The phenomenon of the drive level dependence is discussed in terms of the voltage drive, electric field, power density and current density. It is found that the drive level dependency is best described in terms of the power density. Experimental results for the AT-, BT- and SC-cut resonators in comparison with our model results are presented. Results for new doubly rotated cuts are presented. The effects of spurious modes, quality factor and air damping on DLD are presented

Tree adjunct grammars

In this paper, a tree generating system called a tree adjunct grammar is described and its formal properties are studied relating them to the tree generating systems of Brainerd (Information and Control 14 (1969), 217–231) and Rounds (Mathematical Systems Theory 4 (1970), 257–287) and to the recognizable sets and local sets discussed by Thatcher (Journal of Computer and System Sciences 1 (1967), 317–322; 4 (1970), 339–367) and Rounds. Linguistic relevance of these systems has been briefly discussed also