STOCK PRICES AND EXCHANGE RATES IN AUSTRALIA: ARE COMMODITY PRICES THE MISSING LINK?

The relationship between stock prices and exchange rates is an important topic of long standing. But there are still significant gaps in our knowledge of this area, not least, the ambiguity about the sign of the effect of a change in one of these variables on the other. While there are many possible reasons for this ambiguity, one which we explore in the Australian context in this paper is the omission of commodity prices. We show that a bivariate relationship which omits commodity prices performs badly but that once commodity prices are added to the relationship, our results are plausible and robust. We also throw light on the commodity-currency issue and show that the link from the exchange rate to commodity prices is stronger and more consistent than that in the opposite direction.

Applied geology of the Bismarck-Mandan area, North Dakota

The Bismarck-Mandan area includes about 350 square miles located along both sides of\u27 the Missouri River in south-central North Dakota. The area can be divided into two major physiographic divisions: the broad Missouri River floodplain and the nearly flat uplands which are dissected by minor streams. Geologic units in the area include Upper Cretaceous and lower Tertiary sandstone, siltstone, and shale and Quaternary sand, silt, clay, and gravel. Expansion of residential areas around the cities of Bismarck and Mandan results in conflicts in land-use between agricultural, urban, and resource development. This study consists of detailed geologic maps and a series of interpretive land-use maps that are intended to provide technical input for planning decisions to help resolve these conflicts. The mineral resources include moderate amounts of high-quality sand and gravel, abundant clay, and abundant riprap stone. To insure maximum use of the sand and gravel reserve, residential and industrial de.relopmet1t should not be allowed to cover the deposits. The highest quality water in the area is from the Missouri River. Ground-water can be found in large amounts in shallow Quaternary sand and gravel aquifers that follow the stream valleys. Groundwater is also present in small amounts in shallow aquifers in. the Cannonball and Tongue River Formations and in even smaller am01mts in the Hell Creek Formation. However, the quality of water taken from these bedrock aquifers is usually low. Low-quality water can be produced in large quantities from the Dakota Aquifer, at a depth of about 1000 meters. The best sources for irrigation water are the Missouri River and the sand and gravel aquifers on the Missouri River floodplain. General construction involves few problems on the flat uplands. The bearing strength is generally high and the water table is low. Scattered large granitic boulders cause some excavation problems. Areas where the shale of the Cannonball Formation has been exposed on steep slopes are often subject to slumping and soil creep. Construction problems can also be expected on the flat Missouri River valley and along the other streams. Flooding is common along all the streams except the Missouri River. Water tables are very high and many areas are poorly drained. The bearing strength of most of the materials in the lowlands is low to moderate. Safe waste disposal should be little problem on most of the flat uplands. The at least along the numerous small gullies and intermittent streams should be avoided for landfill or lagoon sites. Problems resulting from shallow water tables and flooding make the lowland areas poorly suited as waste disposal sites

Noncommutative gauge fields coupled to noncommutative gravity

We present a noncommutative (NC) version of the action for vielbein gravity coupled to gauge fields. Noncommutativity is encoded in a twisted star product between forms, with a set of commuting background vector fields defining the (abelian) twist. A first order action for the gauge fields avoids the use of the Hodge dual. The NC action is invariant under diffeomorphisms and twisted gauge transformations. The Seiberg-Witten map, adapted to our geometric setting and generalized for an arbitrary abelian twist, allows to re-express the NC action in terms of classical fields: the result is a deformed action, invariant under diffeomorphisms and usual gauge transformations. This deformed action is a particular higher derivative extension of the Einstein-Hilbert action coupled to Yang-Mills fields, and to the background vector fields defining the twist. Here noncommutativity of the original NC action dictates the precise form of this extension. We explicitly compute the first order correction in the NC parameter of the deformed action, and find that it is proportional to cubic products of the gauge field strength and to the symmetric anomaly tensor D_{IJK}.Comment: 18 pages, LaTe

Noncommutative deformation of four dimensional Einstein gravity

We construct a model for noncommutative gravity in four dimensions, which reduces to the Einstein-Hilbert action in the commutative limit. Our proposal is based on a gauge formulation of gravity with constraints. While the action is metric independent, the constraints insure that it is not topological. We find that the choice of the gauge group and of the constraints are crucial to recover a correct deformation of standard gravity. Using the Seiberg-Witten map the whole theory is described in terms of the vierbeins and of the Lorentz transformations of its commutative counterpart. We solve explicitly the constraints and exhibit the first order noncommutative corrections to the Einstein-Hilbert action.Comment: LaTex, 11 pages, comments added, to appear in Classical and Quantum Gravit

Instruments and channels in quantum information theory

While a positive operator valued measure gives the probabilities in a quantum measurement, an instrument gives both the probabilities and the a posteriori states. By interpreting the instrument as a quantum channel and by using the typical inequalities for the quantum and classical relative entropies, many bounds on the classical information extracted in a quantum measurement, of the type of Holevo's bound, are obtained in a unified manner.Comment: 12 pages, revtex

On the concepts of radial and angular kinetic energies

We consider a general central-field system in D dimensions and show that the division of the kinetic energy into radial and angular parts proceeds differently in the wavefunction picture and the Weyl-Wigner phase-space picture. Thus, the radial and angular kinetic energies are different quantities in the two pictures, containing different physical information, but the relation between them is well defined. We discuss this relation and illustrate its nature by examples referring to a free particle and to a ground-state hydrogen atom.Comment: 10 pages, 2 figures, accepted by Phys. Rev.

The Moyal-Lie Theory of Phase Space Quantum Mechanics

A Lie algebraic approach to the unitary transformations in Weyl quantization is discussed. This approach, being formally equivalent to the $\star$-quantization, is an extension of the classical Poisson-Lie formalism which can be used as an efficient tool in the quantum phase space transformation theory.Comment: 15 pages, no figures, to appear in J. Phys. A (2001

Quantum Mechanics as an Approximation to Classical Mechanics in Hilbert Space

Classical mechanics is formulated in complex Hilbert space with the introduction of a commutative product of operators, an antisymmetric bracket, and a quasidensity operator. These are analogues of the star product, the Moyal bracket, and the Wigner function in the phase space formulation of quantum mechanics. Classical mechanics can now be viewed as a deformation of quantum mechanics. The forms of semiquantum approximations to classical mechanics are indicated.Comment: 10 pages, Latex2e file, references added, minor clarifications mad

Wigner Trajectory Characteristics in Phase Space and Field Theory

Exact characteristic trajectories are specified for the time-propagating Wigner phase-space distribution function. They are especially simple---indeed, classical---for the quantized simple harmonic oscillator, which serves as the underpinning of the field theoretic Wigner functional formulation introduced. Scalar field theory is thus reformulated in terms of distributions in field phase space. Applications to duality transformations in field theory are discussed.Comment: 9 pages, LaTex2