The Yang-Mills Vacuum in Coulomb Gauge in D=2+1 Dimensions

The variational approach to the Hamilton formulation of Yang-Mills theory in Coulomb gauge developed by the present authors previously is applied to Yang-Mills theory in 2+1 dimensions and is confronted with the existing lattice data. We show that the resulting Dyson-Schwinger equations (DSE) yield consistent solutions in 2+1 dimensions only for infrared divergent ghost form factor and gluon energy. The obtained numerical solutions of the DSE reproduce the analytic infrared results and are in satisfactory agreement with the existing lattice date in the whole momentum range.Comment: 20 pages, 6 figure

Infrared analysis of propagators and vertices of Yang--Mills theory in Landau and Coulomb gauge

The infrared behaviour of gluon and ghost propagators, ghost-gluon vertex and three-gluon vertex is investigated for both the covariant Landau and the non-covariant Coulomb gauge. Assuming infrared ghost dominance, we find a unique infrared exponent in the d=4 Landau gauge, while in the d=3+1 Coulomb gauge we find two different infrared exponents. We also show that a finite dressing of the ghost-gluon vertex has no influence on the infrared exponents. Finally, we determine the infrared behaviour of the three-gluon vertex analytically and calculate it numerically at the symmetric point in the Coulomb gauge.Comment: 25 pages, 6 figures, accepted by Phys. Rev. D, references added, typos correcte

Photonic bandgap plasmonic waveguides

A novel type of a plasmonic waveguide has been proposed featuring an "open" design that is easy to manufacture, simple to excite and that offers a convenient access to a plasmonic mode. Optical properties of photonic bandgap (PBG) plasmonic waveguides are investigated experimentally by leakage radiation microscopy and numerically using the finite element method confirming photonic bandgap guidance in a broad spectral range. Propagation and localization characteristics of a PBG plasmonic waveguide have been discussed as a function of the wavelength of operation, waveguide core size and the number of ridges in the periodic reflector for fundamental and higher order plasmonic modes of the waveguide

Corporate Social Responsibility Through an Economic Lens

Business leaders, government officials, and academics are focusing considerable attention on the concept of “corporate social responsibility” (CSR), particularly in the realm of environmental protection. Beyond complete compliance with environmental regulations, do firms have additional moral or social responsibilities to commit resources to environmental protection? How should we think about the notion of firms sacrificing profits in the social interest? May they do so within the scope of their fiduciary responsibilities to their shareholders? Can they do so on a sustainable basis, or will the forces of a competitive marketplace render such efforts and their impacts transient at best? Do firms, in fact, frequently or at least sometimes behave this way, reducing their earnings by voluntarily engaging in environmental stewardship? And finally, should firms carry out such profit-sacrificing activities (i.e., is this an efficient use of social resources)? We address these questions through the lens of economics, including insights from legal analysis and business scholarship.corporate social responsibility, voluntary environmental performance

Gamma spectrometry supported ethnopedological soil mapping in Tanzania

Within the framework of the Trans-SEC project, financed by BMBF, two food value chains for the Dodoma region in Tanzania were inspected in order to make propositions for improvements reaching from soil preparation to product consumption. For this purpose, rapid and reliable soil mapping approaches were established to obtain information for site-adapted cropping trials. A combination of local soil knowledge and gamma spectrometry assisted soil mapping was applied to create soil maps of two villages in the Dodoma region. Local farmers possess decade-old experience and knowledge of the terrain; gamma spectrometry is a proximal, non-invasive method delivering quick results in the field which can be related to soil types and soil properties. In the course of the mapping procedure, soil type distributions in the landscape and laboratory data were related to gamma signals and correlations were investigated. In order to get a first idea of landscape and local soils, focus group discussions were carried out and resulted in a preliminary soil map, drawn together with local farmers on high resolution satellite images. On this basis, reference soil profiles of the major soil types were described, sampled and gamma signatures as fingerprints were recorded. The latter served as reference for later soil distinction in the field. In the next step, transect walks with soil samplings and gamma ray measurements were carried out together with local key informants. In addition, plots for later cropping experiments were investigated with gamma spectrometry and soil sampling. On first hand, gamma signals depended on bedrock composition. The signals were, in second order, altered by weathering processes and led to further interpretation opportunities. Soil gamma signatures served well for soil distinction. In the laboratory, major soil nutrients and properties were determined, i.e. total carbon, total nitrogen, pH and plant-available P and K. Gamma data were explored in detail for interpretation and further information extraction possibilities. Relationships between gamma radiation and soil properties, valid for the study area, but also transferable to other studies were examined

Corporate Social Responsibility Through an Economic Lens

Business leaders, government officials, and academics are focusing considerable attention on the concept of "corporate social responsibility" (CSR), particularly in the realm of environmental protection. Beyond complete compliance with environmental regulations, do firms have additional moral or social responsibilities to commit resources to environmental protection? How should we think about the notion of firms sacrificing profits in the social interest? May they do so within the scope of their fiduciary responsibilities to their shareholders? Can they do so on a sustainable basis, or will the forces of a competitive marketplace render such efforts and their impacts transient at best? Do firms, in fact, frequently or at least sometimes behave this way, reducing their earnings by voluntarily engaging in environmental stewardship? And finally, should firms carry out such profit-sacrificing activities (i.e., is this an efficient use of social resources)? We address these questions through the lens of economics, including insights from legal analysis and business scholarship.Corporate Social Responsibility, Voluntary Environmental Performance

Two-Point Functions of Coulomb Gauge Yang-Mills Theory

The functional approach to Coulomb gauge Yang-Mills theory is considered within the standard, second order, formalism. The Dyson-Schwinger equations and Slavnov-Taylor identities concerning the two-point functions are derived explicitly and one-loop perturbative results are presented.Comment: 12 pages, no figure

Variational solution of the Yang-Mills Schr\"odinger equation in Coulomb gauge

The Yang-Mills Schr\"odinger equation is solved in Coulomb gauge for the vacuum by the variational principle using an ansatz for the wave functional, which is strongly peaked at the Gribov horizon. A coupled set of Schwinger-Dyson equations for the gluon and ghost propagators in the Yang-Mills vacuum as well as for the curvature of gauge orbit space is derived and solved in one-loop approximation. We find an infrared suppressed gluon propagator, an infrared singular ghost propagator and a almost linearly rising confinement potential.Comment: 24 pages, revtex, 13 figure

Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton

We study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after projection'). We evaluate corrected meson fields in the region 300 MeV \le M \le 600 MeV of constituent quark masses M and compare them with the uncorrected fields. We study the effect of the corrections on various expectation values of nuclear observables such as the root-mean square radius, the axial-vector coupling constant, magnetic moments and the delta-nucleon mass splitting.Comment: 19 pages, LaTeX, 7 postscript figures included using 'psfig.sty', to appear in Int.J.Mod.Phys.