New Regulators for Quantum Field Theories with Compactified Extra Dimensions. II: Ultraviolet Finiteness and Effective Field Theory Implementation

In a previous companion paper [arXiv:0712.3532], we proposed two new regulators for quantum field theories in spacetimes with compactified extra dimensions. Unlike most other regulators which have been used in the extra-dimension literature, these regulators are specifically designed to respect the original higher-dimensional Lorentz and gauge symmetries that exist prior to compactification, and not merely the four-dimensional symmetries which remain afterward. In this paper, we use these regulators in order to develop a method for extracting ultraviolet-finite results from one-loop calculations. This method also allows us to derive Wilsonian effective field theories for Kaluza-Klein modes at different energy scales. Our method operates by ensuring that divergent corrections to parameters describing the physics of the excited Kaluza-Klein modes are absorbed into the corresponding parameters for zero modes, thereby eliminating the need to introduce independent counterterms for parameters characterizing different Kaluza-Klein modes. Our effective field theories can therefore simplify calculations involving Kaluza-Klein modes, and be compared directly to potential experimental results emerging from collider data.Comment: 24 pages, LaTeX, 1 figur

The effects of hearing protection on speech intelligibility in noise

Speech intelligibility was investigated in subjects with and without the use of hearing protection in a high noise environment. Fifteen normal hearing subjects and fifteen subjects with high-frequency hearing losses were given the California Consonant Test (CCT) with and without the use of a circurnaural muff-type hearing protector. The CCT was selected as the test stimuli due to its design as a sensitive measure for persons experiencing a high-frequency hearing loss. Testing was conducted in a sound-treated room with the speech and noise stimuli delivered at a high intensity level (85dBA); signal-to-noise ratio was zero. A two-way analysis of variance on the resulting CCT scores indicated a significant difference between the normal hearing subject scores and the hearing impaired subject scores. Statistical significance was also found between the CCT scores obtained with hearing protection and those obtained without hearing protection. Interaction effects between hearing sensitivity and the hearing protection condition were not significant. However, examination of raw score means indicated a trend toward decreased CCT scores with hearing protection use for the hearing impaired subject group. Individual variability in the CCT scores may have accounted for the lack of significance in the interaction effects. A factor in this variability probably was the broad range of muff attenuation values for the experimental subjects. Future research is recommended to identify factors which cause variability in hearing protection attenuation across individual users. Future researchers may also focus upon investigating specific variables such as test stimuli, noise levels, signal-to-noise ratios, types of noise, or types of hearing protection. Research in this area is needed to further study the effects of hearing protection onspeech intelligibility in high noise environments

New Regulators for Quantum Field Theories with Compactified Extra Dimensions. I: Fundamentals

In this paper, we propose two new regulators for quantum field theories in spacetimes with compactified extra dimensions. We refer to these regulators as the ``extended hard cutoff'' (EHC) and ``extended dimensional regularization'' (EDR). Although based on traditional four-dimensional regulators, the key new feature of these higher-dimensional regulators is that they are specifically designed to handle mixed spacetimes in which some dimensions are infinitely large and others are compactified. Moreover, unlike most other regulators which have been used in the extra-dimension literature, these regulators are designed to respect the original higher-dimensional Lorentz and gauge symmetries that exist prior to compactification, and not merely the four-dimensional symmetries which remain afterward. This distinction is particularly relevant for calculations of the physics of the excited Kaluza-Klein modes themselves, and not merely their radiative effects on zero modes. By respecting the full higher-dimensional symmetries, our regulators avoid the introduction of spurious terms which would not have been easy to disentangle from the physical effects of compactification. As part of our work, we also derive a number of ancillary results. For example, we demonstrate that in a gauge-invariant theory, analogues of the Ward-Takahashi identity hold not only for the usual zero-mode (four-dimensional) photons, but for all excited Kaluza-Klein photons as well.Comment: 47 pages, LaTeX, 3 figure

Introduction to the political economy of the sub-prime crisis in Britain : constructing and contesting competence

It is almost always inadvisable to try to second-guess the character of a General Election campaign before it begins in earnest. Yet, even in today’s shadow-boxing phase in advance of the British General Election due to be called in 2010, a number of important campaign contours are already in evidence. It is one of the unwritten laws of British electoral politics that governments unravel – particularly those of a certain longevity – as events appear ever more to have spiralled out of their control. The task for the Brown Government in the upcoming General Election campaign is to try to convince voters that there is still life left within Labour despite its current travails with the credit crunch and British banks’ self-imposed entrapment in the subprime crisis. Claim and counter-claim are likely to pass between the Government and the opposition parties as to where the blame lies for the current disarray of the banking sector, whose model of regulation is most responsible and who is best placed to ensure a successful clean-up operation. Whoever is perceived to have come out on top in this debate is likely to stand a very good chance of winning the election

Integrated Laboratory Demonstrations of Multi-Object Adaptive Optics on a Simulated 10-Meter Telescope at Visible Wavelengths

One important frontier for astronomical adaptive optics (AO) involves methods such as Multi-Object AO and Multi-Conjugate AO that have the potential to give a significantly larger field of view than conventional AO techniques. A second key emphasis over the next decade will be to push astronomical AO to visible wavelengths. We have conducted the first laboratory simulations of wide-field, laser guide star adaptive optics at visible wavelengths on a 10-meter-class telescope. These experiments, utilizing the UCO/Lick Observatory's Multi-Object / Laser Tomography Adaptive Optics (MOAO/LTAO) testbed, demonstrate new techniques in wavefront sensing and control that are crucial to future on-sky MOAO systems. We (1) test and confirm the feasibility of highly accurate atmospheric tomography with laser guide stars, (2) demonstrate key innovations allowing open-loop operation of Shack-Hartmann wavefront sensors (with errors of ~30 nm) as will be needed for MOAO, and (3) build a complete error budget model describing system performance. The AO system maintains a performance of 32.4% Strehl on-axis, with 24.5% and 22.6% at 10" and 15", respectively, at a science wavelength of 710 nm (R-band) over the equivalent of 0.8 seconds of simulation. The MOAO-corrected field of view is ~25 times larger in area than that limited by anisoplanatism at R-band. Our error budget is composed of terms verified through independent, empirical experiments. Error terms arising from calibration inaccuracies and optical drift are comparable in magnitude to traditional terms like fitting error and tomographic error. This makes a strong case for implementing additional calibration facilities in future AO systems, including accelerometers on powered optics, 3D turbulators, telescope and LGS simulators, and external calibration ports for deformable mirrors.Comment: 29 pages, 11 figures, submitted to PAS

Ceiling-fan-integrated air conditioning: Airflow and temperature characteristics of a sidewall-supply jet interacting with a ceiling fan

Ceiling-Fan-Integrated Air Conditioning (CFIAC) is a proposed system that can greatly increase buildings’ cooling efficiency. In it, terminal supply ducts and diffusers are replaced by vents/nozzles, jetting supply air toward ceiling fans that serve to mix and distribute it within the room. Because of the fans’ air movement, the system provides comfort at higher room temperatures than in conventional commercial/ institutional/retail HVAC. We have experimentally evaluated CFIAC in a test room. This paper covers the distributions of air-speed, temperature, and calculated comfort level throughout the room. Two subsequent papers report tests of human subject comfort and ventilation effectiveness in the same experimental conditions. The room’s supply air emerged from a high-sidewall vent directed toward a ceiling fan on the jet centerline; we also tested this same jet on a fan located off to the side of the jet. Primary variables are: ceiling fan flow volumes in downward and upward directions, supply air volume, and room-vs-supply temperature difference. Velocity, turbulence, and temperature distributions are presented for vertical and horizontal transects of the room. The occupied zone is then evaluated for velocity and temperature non-uniformity, and for comfort as predicted by the ASHRAE Standard 55 elevated air speed method. We show that temperatures are well-mixed and uniform across the room for all of the fan-on configurations, for fans both within or out of the supply jet centerline. The ceiling fan flow dominates the CFIAC airflow, and even though non-uniform is capable of providing comfortable conditions throughout the occupied area of the room

The value in de-emphasizing structure in liquidity

In the set of commentaries on liquidity entitled “The continuing significance of social structure in liquid modernity,” three sets of authors set out to examine the relationship between liquidity and structure, value, and distinction. In doing so, they attempt to marry theories which argue against sociologist Zygmunt Bauman’s central thesis that societal structures are shifting with his seminal construct of liquidity, an exercise that has mixed results. All three sets of authors have engaged with Bauman’s conceptualization of liquid modernity as well as our conceptualization of liquid consumption and its consequences. In this response to the commentaries, we clarify how we understand Bauman and how we have used his ideas in our theorizing, engage with the three sets of author’s advocacy for emphasizing the continuing relevance of structure within liquidity, and, finally, sum up how de-emphasizing structure has and can continue to lead to important new insights in marketing theory