Lorentz Violation at One Loop

The proof of one-loop renormalizability of the general Lorentz- and CPT-violating extension of quantum electrodynamics is described. Application of the renormalization-group method is discussed and implications for theory and experiment are considered.Comment: 10 pages, 28 figures, latex, uses sprocl.sty (included), talk presented at the Second Meeting on CPT and Lorentz Symmetry, Bloomington, IN, August 200

Stringent Restriction from the Growth of Large-Scale Structure on Apparent Acceleration in Inhomogeneous Cosmological Models

Probes of cosmic expansion constitute the main basis for arguments to support or refute a possible apparent acceleration due to different expansion rates in the universe as described by inhomogeneous cosmological models. We present in this Letter a separate argument based on results from an analysis of the growth rate of large-scale structure in the universe as modeled by the inhomogeneous cosmological models of Szekeres. We use the models with no assumptions of spherical or axial symmetries. We find that while the Szekeres models can fit very well the observed expansion history without a $\Lambda$, they fail to produce the observed late-time suppression in the growth unless $\Lambda$ is added to the dynamics. A simultaneous fit to the supernova and growth factor data shows that the cold dark matter model with a cosmological constant ($\Lambda$CDM) provides consistency with the data at a confidence level of 99.65% while the Szekeres model without $\Lambda$ achieves only a 60.46% level. When the data sets are considered separately, the Szekeres with no $\Lambda$ fits the supernova data as well as the $\Lambda$CDM does, but provides a very poor fit to the growth data with only 31.31% consistency level compared to 99.99% for the $\Lambda$CDM. This absence of late-time growth suppression in inhomogeneous models without a $\Lambda$ is consolidated by a physical explanation.Comment: 5 pages, 1 figure, matches version published in PR

11B and Constraints on Neutrino Oscillations and Spectra from Neutrino Nucleosynthesis

We have studied the sensitivity to variations in the triple alpha and 12C(alpha, gamma)16O reaction rates, of the yield of the neutrino process isotopes 7Li,11B, 19F, 138La, and 180Ta in core collapse supernovae. Compared to solar abundances, less than 15% of 7Li, about 25-80% of 19F, and about half of 138La is produced in these stars. Over a range of two sigma for each helium-burning rate, 11B is overproduced and the yield varies by an amount larger than the variation caused by the effects of neutrino oscillations. The total 11B yield, however, may eventually provide constraints on supernova neutrino spectra

Chemical structure matching using correlation matrix memories

This paper describes the application of the Relaxation By Elimination (RBE) method to matching the 3D structure of molecules in chemical databases within the frame work of binary correlation matrix memories. The paper illustrates that, when combined with distributed representations, the method maps well onto these networks, allowing high performance implementation in parallel systems. It outlines the motivation, the neural architecture, the RBE method and presents some results of matching small molecules against a database of 100,000 models