1,848 research outputs found
Yang--Mills Configurations from 3D Riemann--Cartan Geometry
Recently, the {\it spacelike} part of the Yang--Mills equations has
been identified with geometrical objects of a three--dimensional space of
constant Riemann--Cartan curvature. We give a concise derivation of this
Ashtekar type (``inverse Kaluza--Klein") {\it mapping} by employing a
--decomposition of {\it Clifford algebra}--valued torsion and curvature
two--forms. In the subcase of a mapping to purely axial 3D torsion, the
corresponding Lagrangian consists of the translational and Lorentz {\it
Chern--Simons term} plus cosmological term and is therefore of purely
topological origin.Comment: 14 pages, preprint Cologne-thp-1994-h1
Experimental application of LANDSAT to geobotanical prospecting of serpentine outcrops in the central Appalachian Piedmont of North America
The use of LANDSAT as a tool for geobotanical prospecting was studied in a 13,137 sq km area from southeastern Pennsylvania to northern Virginia. Vegetation differences between known serpentine and non-sepentine sites were most easily distinguished on early summer images. A multispectral signature was derived from vegetation of two known serpentine sites and a map was produced of 159 similar signatures of vegetation in the study area. Authenticity of the serpentine nature of the mapped sites was checked via geochemical analysis of collected soils from 14% of the sites. Overall success of geobotanical prospecting was about 35% for the total study area. When vegetation distribution was taken into account, the success rate was 67% for the region north of the Potomac, demonstrates the effectiveness of the multispectral satellite for quickly and accurately locating mineral sensitive vegetation communities over vast tracts of land
On the chiral anomaly in non-Riemannian spacetimes
The translational Chern-Simons type three-form coframe torsion on a
Riemann-Cartan spacetime is related (by differentiation) to the Nieh-Yan
four-form. Following Chandia and Zanelli, two spaces with non-trivial
translational Chern-Simons forms are discussed. We then demonstrate, firstly
within the classical Einstein-Cartan-Dirac theory and secondly in the quantum
heat kernel approach to the Dirac operator, how the Nieh-Yan form surfaces in
both contexts, in contrast to what has been assumed previously.Comment: 18 pages, RevTe
- …