Reconstruction of interacting dark energy models from parameterizations

Models with interacting dark energy can alleviate the cosmic coincidence problem by allowing dark matter and dark energy to evolve in a similar fashion. At a fundamental level, these models are specified by choosing a functional form for the scalar potential and for the interaction term. However, in order to compare to observational data it is usually more convenient to use parameterizations of the dark energy equation of state and the evolution of the dark matter energy density. Once the relevant parameters are fitted it is important to obtain the shape of the fundamental functions. In this paper I show how to reconstruct the scalar potential and the scalar interaction with dark matter from general parameterizations. I give a few examples and show that it is possible for the effective equation of state for the scalar field to cross the phantom barrier when interactions are allowed. I analyze the uncertainties in the reconstructed potential arising from foreseen errors in the estimation of fit parameters and point out that a Yukawa-like linear interaction results from a simple parameterization of the coupling.Comment: 6 pages, 8 figure

The sudden approximation applied to molecular problems. I - Non-reactive collisions

Sudden approximation for calculating transition probabilities for energy transfer during collisions between molecules and atom

Pattern recognition- iv. sequential operations in digital picture processing

Sequential approach to digital picture processin

Plants for predators - a participatory experiment

Encouraging natural enemies by growing attractant plants is a highly effective method of pest control in organic systems. However, it is important to establish which plants are most effective at attracting benefi cial insects. Experiments were carried out by 179 HDRA members, who grew four plant species (Coriander, Corn Marigold, Fennel and Phacelia) in their gardens and allotments. Over the course of the growing season, assessments were made on the growth and flowering of the plants and the presence of four key groups of beneficial insect (ladybirds, hoverflies, lacewings and parasitic wasps). Phacelia established quickly and its long flowering period meant it attracted insects throughout the summer. However, Phacelia was only the most attractive plant at the end of the season and insects preferred the other trial plants when they were in flower. Results highlight the importance of growing a range of flowering plants to provide resources for beneficials throughout their activity period

Observations of shallow convective clouds generated by solar heating of dark smoke plumes

The SEVIRI instrument on the Meteosat Second Generation satellite with both fine spatial and temporal resolution allows to detect and follow the dynamics of fast developing meteorological events like spreading smoke plumes and the lifecycles of convective clouds. Smoke plumes have the ability to change the atmospheric heat content due to absorption and reduced reflection of solar radiation. By these means they can trigger formation of shallow convective clouds at their edge. A heavy smoke plume emerging from burning Lebanese oil tanks and spreading over adjacent deserts on 17 July 2006 has been observed as an example of such an effect. This study suggests a physical explanation of the observed convection along the edge of the smoke plume, namely the strong thermal contrast resulting from solar heating of the smoke layer

Correlation energy of two-electron systems

Correlation energy of two-electron system

Pattern recognition. v- samp - a computer program for estimating surface area from contour maps

Fortran computer program for computing linear approximation of surface area for any given portion of digitized contour ma

Rotated Garnets and Tectonism in Southeast Vermont

Guidebook for field trips in Vermont: 64th annual meeting October 13, 14, 15, 1972 Burlington, Vermont: Trip B-