Dilaton Stabilization in Brane Gas Cosmology

Brane Gas Cosmology is an M-theory motivated attempt to reconcile aspects of the standard cosmology based on Einstein's theory of general relativity. Dilaton gravity, when incorporating winding p-brane states, has verified the Brandenberger--Vafa mechanism --a string-motivated conjecture which explains why only three of the nine spatial dimensions predicted by string theory grow large. Further investigation of this mechanism has argued for a hierarchy of subspaces, and has shown the internal directions to be stable to initial perturbations. These results, however, are dependent on a rolling dilaton, or varying strength of Newton's gravitational constant. In these proceedings we show that it is not possible to stabilize the dilaton and maintain the stability of the internal directions within the standard Brane Gas Cosmology setup.Comment: 6 pages, no figures. To appear in the Proceedings of MRST 2004, held at Concordia University, Montreal, QC, 12-14 May 200

Beyond the rainbow: effects from pion back-coupling

We investigate hadronic unquenching effects in light quarks and mesons. To this end we take into account the back-coupling of the pion onto the quark propagator within the non-perturbative continuum framework of Schwinger-Dyson equations (SDE) and Bethe-Salpeter equations (BSE). We improve on a previous approach by explicitly solving both the coupled system of DSEs and BSEs in the complex plane and the normalisation problem for Bethe-Salpeter kernels depending on the total momentum of the meson. As a result of our study we find considerable unquenching effects in the spectrum of light pseudoscalar, vector and axial-vector mesons.Comment: 9 pages, 5 figures. Minor typos corrected. Version to appear in PR

Grain marketing and National Competition Policy: reform or reaction?

Grain marketing arrangements in Australia have been controversial for many years. Following an account of the historical background to grain marketing, this article concentrates on more recent debates. The most interesting technical economic argument concerns the validity of claims that statutory marketing authorities with export monopoly powers can obtain higher prices. The article also discusses how marketing in Australia has been affected by Commonwealth and State Government policies with respect to microeconomic reform and privatization. Although major changes appear to have been made in grain marketing and its institutions, there are inherent economic problems with the current approach to deregulation.Crop Production/Industries, Marketing,

Productivity of Federally Financed Research and Development Final Report, May 15, 1963 - May 14, 1966

Research project on federal and industrial patent acquisition and economic implications - NASA PROGRA

Effective Field Theory Approach to String Gas Cosmology

We derive the 4D low energy effective field theory for a closed string gas on a time dependent FRW background. We examine the solutions and find that although the Brandenberger-Vafa mechanism at late times no longer leads to radion stabilization, the radion rolls slowly enough that the scenario is still of interest. In particular, we find a simple example of the string inspired dark matter recently proposed by Gubser and Peebles.Comment: 19 pages, 2 figures, comments adde