Integrals of Motion in the Two Killing Vector Reduction of General Relativity

We apply the inverse scattering method to the midi-superspace models that are characterized by a two-parameter Abelian group of motions with two spacelike Killing vectors. We present a formulation that simplifies the construction of the soliton solutions of Belinski\v i and Zakharov. Furthermore, it enables us to obtain the zero curvature formulation for these models. Using this, and imposing periodic boundary conditions corresponding to the Gowdy models when the spatial topology is a three torus $T ^3$, we show that the equation of motion for the monodromy matrix is an evolution equation of the Heisenberg type. Consequently, the eigenvalues of the monodromy matrix are the generating functionals for the integrals of motion. Furthermore, we utilise a suitable formulation of the transition matrix to obtain explicit expressions for the integrals of motion. This involves recursion relations which arise in solving an equation of Riccati type. In the case when the two Killing vectors are hypersurface orthogonal the integrals of motion have a particularly simple form.Comment: 20 pages, plain TeX, SU-GP-93/7-8, UM-P-93/7

S98RS SGR No. 12 (Easter Holidays)

A RESOLUTION To recommend to Executive Vice-Chancellor and Provost Dan Fogel, Robert Doolos of the University’s Registrar’s Office, and the University Calendar Committee to extend the Easter holiday through the Monday following Easter Sunday

Asymptotic Behaviour of Inhomogeneous String Cosmologies

The asymptotic behaviour at late times of inhomogeneous axion-dilaton cosmologies is investigated. The space-times considered here admit two abelian space-like Killing vectors. These space-times evolve towards an anisotropic universe containing gravitational radiation. Furthermore, a peeling-off behaviour of the Weyl tensor and the antisymmetric tensor field strength is found. The relation to the pre-big-bang scenario is briefly discussed.Comment: 15 pages, Late

Mirror Images of String Cosmologies

A discrete symmetry of the four-dimensional string effective action is employed to derive spatially homogeneous and inhomogeneous string cosmologies from vacuum solutions of general relativity that admit two commuting spacelike Killing vectors. In particular, a tilted Bianchi type V cosmology is generated from a vacuum type VI_h solution and a plane wave solution with a bounded and oscillating dilaton field is found from a type ${\rm VII}_h$ model. Further applications are briefly discussed.Comment: 10 pages plain late

S98RS SGR No. 13 (Admissons Standard)

A RESOLUTION To encourage the University Administration, the Office of Admissions, the Office of Academic Affairs, and the LSU A & M faculty to create a more stringent, uniform standard of admission for entering students

Superstring Cosmology

Aspects of superstring cosmology are reviewed with an emphasis on the cosmological implications of duality symmetries in the theory. The string effective actions are summarized and toroidal compactification to four dimensions reviewed. Global symmetries that arise in the compactification are discussed and the duality relationships between the string effective actions are then highlighted. Higher-dimensional Kasner cosmologies are presented and interpreted in both string and Einstein frames, and then given in dimensionally reduced forms. String cosmologies containing both non-trivial Neveu-Schwarz/Neveu-Schwarz and Ramond-Ramond fields are derived by employing the global symmetries of the effective actions. Anisotropic and inhomogeneous cosmologies in four-dimensions are also developed. The review concludes with a detailed analysis of the pre-big bang inflationary scenario. The generation of primordial spectra of cosmological perturbations in such a scenario is discussed. Possible future directions offered in the Horava-Witten theory are outlined.Comment: 161 pages, latex with epsf, 15 figures. Minor changes, additional references and figures. Version to appear in Physics Report

Generating techniques in vacuum and stiff perfect fluid cosmologies

SIGLEAvailable from British Library Document Supply Centre-DSC:DX194531 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Tūrangawaewae : exploring the relationship between two indigenous cultures, and their connection to their ancestral land

RESEARCH QUESTION: How can one culture’s architecture be built in another culture’s landscape, when both groups’ identities are tied to their ancestral lands? ABSTRACT: This research explores New Zealand Māori and Australian Aboriginal peoples’ connection to their ancestral land, and how their relationship to the land has changed, and continues to change, over time. The overall master planning and design of a Marae Cultural Centre, sited on significant Aboriginal Darug land in Western Sydney, is developed through the use of Glenn Murcutt’s philosophy of designing to respond to the site and to ‘touch the earth lightly.’ There is a particular focus on the marae atea as a forum for bi-cultural expression and interaction. An analysis of traditional building techniques, and how they can be adapted using modern systems and materials is also explored. This gives a construction detail focused architectural outcome which complements the overall master planning and environmental design drivers of the project