Long Range Forces in Quantum Gravity

We calculate the leading quantum and semi-classical corrections to the Newtonian potential energy of two widely separated static masses. In this large-distance, static limit, the quantum behaviour of the sources does not contribute to the quantum corrections of the potential. These arise exclusively from the propagation of massless degrees of freedom. Our one-loop result is based on Modanese's formulation and is in disagreement with Donoghue's recent calculation. Also, we compare and contrast the structural similarities of our approach to scattering at ultra-high energy and large impact parameter. We connect our approach to results from string perturbation theory.Comment: 26 pages, REVTEX, six PostScript figures in separate uuencoded file or by mail from <[email protected]

On the Laplace transform of absolutely monotonic functions

We obtain necessary and sufficient conditions on a function in order that it be the Laplace transform of an absolutely monotonic function. Several closely related results are also given.Comment: 15 page

Short-term nitrous oxide emissions from pasture soil as influenced by urea level and soil nitrate

Nitrogen excreted by cattle during grazing is a significant source of atmospheric nitrous oxide (N2O). The regulation of N2O emissions is not well understood, but may vary with urine composition and soil conditions. This laboratory study was undertaken to describe short-term effects on N2O emissions and soil conditions, including microbial dynamics, of urea amendment at two different rates (22 and 43 g N m-2). The lower urea concentration was also combined with an elevated soil NO3- concentration. Urea solutions labelled with 25 atom% 15N were added to the surface of repacked pasture soil cores and incubated for 1, 3, 6 or 9 days under constant conditions (60% WFPS, 14°C). Soil inorganic N (NH4+, NO2- and NO3-), pH, electrical conductivity and dissolved organic C were quantified. Microbial dynamics were followed by measurements of CO2 evolution, by analyses of membrane lipid (PLFA) composition, and by measurement of potential ammonium oxidation and denitrifying enzyme activity. The total recovery of 15N averaged 84%. Conversion of urea-N to NO3- was evident, but nitrification was delayed at the highest urea concentration and was accompanied by an accumulation of NO2-. Nitrous oxide emissions were also delayed at the highest urea amendment level, but accelerated towards the end of the study. The pH interacted with NH4+ to produce inhibitory concentrations of NH3(aq) at the highest urea concentration, and there was evidence for transient negative effects of urea amendment on both nitrifying and denitrifying bacteria in this treatment. However, PLFA dynamics indicated that initial inhibitory effects were replaced by increased microbial activity and net growth. It is concluded that urea-N level has qualitative, as well as quantitative effects on soil N transformations in urine patches

Woodin for strong compactness cardinals

We give the definition of Woodin for strong compactness cardinals, the Woodinised version of strong compactness, and we prove an analogue of Magidor's identity crisis theorem for the first strongly compact cardinal.Comment: 20 pages, fixed proof of Theorem 4.1, minor corrections and addition

On Entropy Minimization and Convergence

We examine the minimization of information entropy for measures on the phase space of bounded domains, subject to constraints that are averages of grand canonical distributions. We describe the set of all such constraints and show that it equals the set of averages of all probability measures absolutely continuous with respect to the standard measure on the phase space (with the exception of the measure concentrated on the empty configuration). We also investigate how the set of constrains relates to the domain of the microcanonical thermodynamic limit entropy. We then show that, for fixed constraints, the parameters of the corresponding grand canonical distribution converge, as volume increases, to the corresponding parameters (derivatives, when they exist) of the thermodynamic limit entropy. The results hold when the energy is the sum of any stable, tempered interaction potential that satisfies the Gibbs variational principle (e.g.~Lennard-Jones) and the kinetic energy. The same tools and the strict convexity of the thermodynamic limit pressure for continuous systems (valid whenever the Gibbs variational principle holds) give solid foundation to the folklore local homeomorphism between thermodynamic and macroscopic quantities.Comment: Section 2 revised and improved. The rest of the article has been rewritten accordingly. 22 pages, 2 figure