Covariant And Local Field Theory On The World Sheet

In earlier work, using the light cone picture, a world sheet field theory that sums planar phi^3 graphs was constructed and developed. Since this theory is both non-local and not explicitly Lorentz invariant, it is desirable to have a covariant and local alternative. In this paper, we construct such a covariant and local world sheet theory, and show that it is equivalent to the original non-covariant version.Comment: 22 pages,3 figures, typos and eqs.(11) and (63) are correcte

Field Theory On The World Sheet: Improvements And Generalizations

This article is the continuation of a project of investigating planar phi^3 model in various dimensions. The idea is to reformulate them on the world sheet, and then to apply the classical (meanfield) approximation, with two goals: To show that the ground state of the model is a solitonic configuration on the world sheet, and the quantum fluctuations around the soliton lead to the formation of a transverse string. After a review of some of the earlier work, we introduce and discuss several generalizations and new results. In 1+2 dimensions, a rigorous upper bound on the solitonic energy is established. A phi^4 interaction is added to stabilize the original phi^3 model. In 1+3 and 1+5 dimensions, an improved treatment of the ultraviolet divergences is given. And significantly, we show that our approximation scheme can be imbedded into a systematic strong coupling expansion. Finally, the spectrum of quantum fluctuations around the soliton confirms earlier results: In 1+2 and 1+3 dimensions, a transverse string is formed on the world sheet.Comment: 29 pages, 5 figures, several typos and eqs.(74) and (75) are corrected, a comment added to section

More On The Connection Between Planar Field Theory And String Theory

We continue work on the connection between world sheet representation of the planar phi^3 theory and string formation. The present article, like the earlier work, is based on the existence of a solitonic solution on the world sheet, and on the zero mode fluctuations around this solution. The main advance made in this paper is the removal of the cutoff and the transition to the continuum limit on the world sheet. The result is an action for the modes whose energies remain finite in this limit (light modes). The expansion of this action about a dense background of graphs on the world sheet leads to the formation of a string.Comment: 27 pages, 3 figure

Defining the Force between Separated Sources on a Light Front

The Newtonian character of gauge theories on a light front requires that the longitudinal momentum P^+, which plays the role of Newtonian mass, be conserved. This requirement conflicts with the standard definition of the force between two sources in terms of the minimal energy of quantum gauge fields in the presence of a quark and anti-quark pinned to points separated by a distance R. We propose that, on a light front, the force be defined by minimizing the energy of gauge fields in the presence of a quark and an anti-quark pinned to lines (1-branes) oriented in the longitudinal direction singled out by the light front and separated by a transverse distance R. Such sources will have a limited 1+1 dimensional dynamics. We study this proposal for weak coupling gauge theories by showing how it leads to the Coulomb force law. For QCD we also show how asymptotic freedom emerges by evaluating the S-matrix through one loop for the scattering of a particle in the N_c representation of color SU(N_c) on a 1-brane by a particle in the \bar N_c representation of color on a parallel 1-brane separated from the first by a distance R<<1/Lambda_{QCD}. Potential applications to the problem of confinement on a light front are discussed.Comment: LaTeX, 15 pages, 12 figures; minor typos corrected; numerical correction in equation 3.

Bag Model for a Link in a Closed Gluonic Chain

The large $N_c$ limit of Yang-Mills gauge theory is the dynamics of a closed gluonic chain, but this fact does not obviate the inherently strong coupling nature of the dynamical problem. However, we suggest that a single link in such a chain might be reasonably described in the quasi-perturbative language of gluons and their interactions. To implement this idea, we use the MIT bag to model the physics of a nearest neighbor bond.Comment: 10 pages, LaTe

Pasture research programme for the medium rainfall zone of WA

Field Assistants: I.R. Rose S.P. Davis Soil Analysis: I.A. Pritchard. A. Screening trials M. polymorpha var brevispina. M. truncatula. T. cherleri - 84KA41, 84KA42, 84KA43, 84KA47. B. Large scale M. polymorpha evaluation - 84KA38, 84KA39, 84KA40, C. Long term Medic species evaluation - 82KA44, 82KA45. D. Species characterization trials - 83KA66, 83KA67. E. M. murex evaluation - 83KA45. F. Dwalganup replacement subclovers - 83KA69. Since 1981, the major emphasis of the Katanning pasture programme has been to select pasture species suitable for replacing ryegrass on soils where Annual Ryegrass Toxicity (ARGT) has been a major problem. These soils have traditionally been the hardsetting sandy loam soils of acid to alkaline reaction trend. Subterranean clover has failed to persist in these areas due to problems of burr burial, transient waterlogging and a lack of hardseededness. Screening work to date has successfully identified the species Medicago polymorpha var brevispina to be a suitable alternative to ryegrass and as such, a considerable proportion of resources were directed into a more detailed evaluation of the species

Pasture research programme for the medium rainfall zone of W.A. species selection and management related in particular to the ryegrass toxicity problem (Fund 492/0035).

Species evaluation, 85KA69, 85 KA 70, 85 KA 94, 85 KA 68. Small plot evaluation, 85 KA 89, 8S KA 90. Long term medic species evaluation, 82 KA 44, 82 KA 45. Drill run evaluation of M. polymorpha, 84 KA 38, 84 KA 39, 84 KA 40. Species characterization trials, 83 KA 66, 83 KA 67. Serradella evaluation, 85 KA 72, 85 KA 73, 85 KA 74, 85 KA 7

Development Of Master’s Programs In Sustainable Engineering

During the 2006-2007 academic year, a team of faculty from the Kate Gleason College of Engineering developed a proposal for a pair of Master’s programs (a Master of Science program and a Master of Engineering proposal) in the field of Sustainable Engineering. Sustainable Engineering has been described as “engineering for human development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [3]. Both programs are multidisciplinary in nature and include coursework from the disciplines of Industrial and Systems Engineering, Mechanical Engineering, Civil Engineering Technology, and Public Policy. The programs offer students the flexibility to develop ‘tracks’ in their program of study which would permit deeper immersion in domains such as renewable energy systems, systems modeling and analysis, product design, etc. Student interest in the programs has been very favorable. This paper describes the context at RIT from which the idea for these programs arose, the program development process that was followed, and the structure of the two programs

Farm systems research involving new pasture species.

The effect of grazing on Circle Valley medic production. Effect of rotations on M. polyrnorpha production and persistence and cereal crop yields, 84 KA 35, 85 LG 44, 84 KA 37 Effect of tillage x gypsum x nitrogen on continuous cereal production, 84 KA 28. Effect of gypsum x seeding rate on the seed yield of three pasture legumes. Pasture species tolerance to grass and broadleaf herbicides. Undersowing cereal crops with burr medic

Regularized Green's Function for the Inverse Square Potential

A Green's function approach is presented for the D-dimensional inverse square potential in quantum mechanics. This approach is implemented by the introduction of hyperspherical coordinates and the use of a real-space regulator in the regularized version of the model. The application of Sturm-Liouville theory yields a closed expression for the radial energy Green's function. Finally, the equivalence with a recent path-integral treatment of the same problem is explicitly shown.Comment: 10 pages. The final section was expande