Strong obstruction of the Berends-Burgers-van Dam spin-3 vertex

In the eighties, Berends, Burgers and van Dam (BBvD) found a nonabelian cubic vertex for self-interacting massless fields of spin three in flat spacetime. However, they also found that this deformation is inconsistent at higher order for any multiplet of spin-three fields. For arbitrary symmetric gauge fields, we severely constrain the possible nonabelian deformations of the gauge algebra and, using these results, prove that the BBvD obstruction cannot be cured by any means, even by introducing fields of spin higher (or lower) than three.Comment: 19 pages, no figur

Navigating the Fourth Dimension: Nonlinear Narratives in Film, Literature, and Television

Time is often considered the fourth dimension due to the fact that nothing can exist outside the confines of time. Since time is so intrinsic to the very nature of being in the world, creators of film, literature, and television, which are reflective of life, must at least implicitly confront concepts of time and temporality within their work. The intangibility of time presents many difficulties but also a great number of opportunities in accurately portraying its true function within the world. Many literary works, films, and television programs directly confront concepts of time. Each medium with its own benefits and detriments must approach time and its true representation differently. Although authors and directors all must work within the same confines of their respective media, the approaches taken by different authors and directors are varied and widespread. These diverse approaches vary in their level of success and by which elements regarding the complexity of time they elucidate. It is this introspection into the complexity of time through literature, film, and television, which is the topic of my honors project. By reading novels and viewing films and television programs, which utilize nonlinear story telling techniques and analyzing these works, it is my hope to garner a greater understanding of how the complex nature and experience of time can be approached and re-presented through different media

On Dual Formulation of Gravity

In this paper we consider a possibility to construct dual formulation of gravity where the main dynamical field is the Lorentz connection \omega_\mu^{ab} and not that of tetrad e_\mu^a or metric g_\mu\nu. Our approach is based on the usual dualization procedure which uses first order parent Lagrangians but in (Anti) de Sitter space and not in the flat Minkowski one. It turns out that in d=3 dimensions such dual formulation is related with the so called exotic parity-violating interactions for massless spin-2 particles.Comment: 7 pages, plain LaTe

Oxygen in dense interstellar gas - the oxygen abundance of the star forming core rho Oph A

Oxygen is the third most abundant element in the universe, but its chemistry in the interstellar medium is still not well understood. In order to critically examine the entire oxygen budget, we attempt here initially to estimate the abundance of atomic oxygen, O, in the only one region, where molecular oxygen, O2, has been detected to date. We analyse ISOCAM-CVF spectral image data toward rho Oph A to derive the temperatures and column densities of H2 at the locations of ISO-LWS observations of two [OI] 3P_J lines. The intensity ratios of the (J=1-2) 63um to (J=0-1) 145um lines largely exceed ten, attesting to the fact that these lines are optically thin. This is confirmed by radiative transfer calculations, making these lines suitable for abundance determinations. For that purpose, we calculate line strengths and compare them to the LWS observations. Excess [OI] emission is observed to be associated with the molecular outflow from VLA 1623. For this region, we determine the physical parameters, T and N(H2), from the CAM observations and the gas density, n(H2), is determined from the flux ratio of the [O I]63um and [O I]145um lines. For the oxygen abundance, our analysis leads to essentially three possibilities: (1) Extended low density gas with standard ISM O-abundance, (2) Compact high density gas with standard ISM O-abundance and (3) Extended high density gas with reduced oxygen abundance, [O/H] ~ 2E-5. As option (1) disregards valid [O I] 145um data, we do not find it very compelling; we favour option (3), as lower abundances are expected as a result of chemical cloud evolution, but we are not able to dismiss option (2) entirely. Observations at higher angular resolution than offered by the LWS are required to decide between these possibilities.Comment: Accepted for publication in A&

Relative Effectiveness of Repellents for Preventing Deer Damage to Japanese Yews

Homeowners whose landscape plants are repeatedly browsed by white-tailed deer (Odocoileus virginianus) are interested in repellent products that are effective and long-lasting. New products come to market with limited experimental testing. We conducted a 10-week trial from Feb. through Apr. 1999 to test the duration and efficacy of six commercial deer repellents [Deer-Away Big Game Repellent (BGR) mix, BGR spray, Deer-Off, Deer Stopper II, Repellex, Tree Guard] and two experimental deer repellents (CU-A and CU-B) relative to each other and to untreated plants. Treated and control balled japanese yew (Taxus cuspidata) shrubs were placed at each of 10 homeowner sites with known white-tailed deer damage near Ithaca, NY. Yews are frequently eaten by deer during winter and provide a good bioassay for testing repellents, especially during the winter months. We checked shrubs once weekly and took photographs of damaged yews to measure the amount of deer browsing. We calculated the surface area of shrubs in each photograph by using digital analysis software. To determine significant differences over time, we applied statistical analysis using analysis of variance. Deer repellents that provided the most consistent protection were BGR spray, BGR mix, Deer-Off, and Deer Stopper II. The japanese pachysandra (Pachysandra terminalis) extracts in experimental repellents CU-A and CU-B were not effective. The performance of other commercial repellents varied considerably among sites, and these products were unreliable

Calibrated Dynamic Response Analysis of Stafford Dam

Stafford Dam, an approximately 79-ft high compacted earthfill founded on stream alluvium approximately 40 feet thick, was shaken by the 1989 Lorna Prieta Earthquake. Records of the earthquake motions were obtained from seismographs located at the dam crest and at the right abutment on rock. Two-dimensional dynamic finite element analyses were performed to calibrate a model of the dam using the recorded motions. Excellent agreement between the recorded and calculated response was obtained by appropriate adjustments to material parameters based on shear wave velocity measurements. Various deconvolution methods for obtaining input bedrock motions to calculate the dam response are discussed

On Dual Formulations of Massive Tensor Fields

In this paper we investigate dual formulations for massive tensor fields. Usual procedure for construction of such dual formulations based on the use of first order parent Lagrangians in many cases turns out to be ambiguous. We propose to solve such ambiguity by using gauge invariant description of massive fields which works both in Minkowski space as well as (Anti) de Sitter spaces. We illustrate our method by two concrete examples: spin-2 "tetrad" field h_{\mu a}, the dual field being "Lorentz connection" \omega_{\mu,ab} and "Riemann" tensor R_{\mu\nu,ab} with the dual \Sigma_{\mu\nu,abc}.Comment: 9 pages, plain LaTe

Line-of-Sight Reddening Predictions: Zero Points, Accuracies, the Interstellar Medium, and the Stellar Populations of Elliptical Galaxies

Revised (B-V)_0-Mg_2 data for 402 elliptical galaxies are given to test reddening predictions which can also tell us both what the intrinsic errors are in this relationship among gE galaxy stellar populations, as well as details of nearby structure in the interstellar medium (ISM) of our Galaxy and of the intrinsic errors in reddening predictions. Using least-squares fits, the explicit 1-sigma errors in the Burstein-Heiles (BH) and the Schlegel et al. (IR) predicted reddenings are calculated, as well as the 1-sigma observational error in the (B-V)_0-Mg_2 for gE galaxies. It is found that, in directions with E(B-V)<0.100 mag (where most of these galaxies lie), 1-sigma errors in the IR reddening predictions are 0.006 to 0.009 in E(B-V) mag, those for BH reddening prediction are 0.011 mag, and the 1-sigma agreement between the two reddening predictions is 0.007 mag. IR predictions have an accuracy of 0.010-0.011 mag in directions with E(B-V)>= 0.100 mag, significantly better than those of the BH predictions (0.024-0.025). Gas-to-dust variations that vary by a factor of 3, both high and low, exist along many lines-of-sight in our Galaxy. The approx 0.02 higher reddening zero point in E(B-V) previously determined by Schlegel et al. is confirmed, primarily at the Galactic poles. Despite this, both methods also predict many directions with E(B-V)<0.015 mag. Independent evidence of reddening at the North Galactic pole is reviewed, with the conclusion that there still exists directions at the NGP that have E(B-V)<<0.01. Two lines of evidence suggest that IR reddenings are overpredicted in directions with high gas-to-dust ratios. As high gas-to-dust directions in the ISM also include the Galactic poles, this overprediction is the likely cause of the E(B-V) = 0.02 mag larger IR reddening zero point.Comment: 5 figure

On the band-to-continuum intensity ratio in the infrared spectra of interstellar carbonaceous dust

Published interpretations of the relative intensity variations of the Unidentified Infrared Bands (UIBs) and their underlying continuum are discussed. An alternative model is proposed, in which a single carrier for both emits a) mostly a continuum when it is electronically excited by photons (visible or UV), or b) exclusively the UIBs, when only chemical energy is deposited by H capture on its surface, inducing only nuclear vibrations. The bands will dominate in atomic H regions but will be overcome by thermal continuum radiation when the ambient field is strong but lacks dissociating photons (900-1100 Angstroms). The model applies to PDRs as well as to limbs of molecular clouds in the ISM and agrees quantitatively with recent satellite observations. It gives indications on atomic H density and UIB intensity provided the ambient radiation field is known. It invokes no chemical, electronic, structural or size change in order to interpret the observed intensity variations.Comment: 18 pages, 2 figure