10 research outputs found

    Infinite temperature limit of meson spectral functions calculated on the lattice

    Full text link
    We analyze the cut-off dependence of mesonic spectral functions calculated at finite temperature on Euclidean lattices with finite temporal extent. In the infinite temperature limit we present analytic results for lattice spectral functions calculated with standard Wilson fermions as well as a truncated perfect action. We explicitly determine the influence of `Wilson doublers' on the high momentum structure of the mesonic spectral functions and show that this cut-off effect is strongly suppressed when using an improved fermion action.Comment: 25 pages, 8 figure

    DYSMON II. Dynamik in Sulfid- und Methanbiotopen der Ost- und Nordsee. Abschlussbericht. Bd. 1

    No full text
    Working from the results of DYSMON I the purpose of the DYSMON II project was to examine the emergence of sulphidic, low-oxygen environments and microorganismic and faunal responses to this. The focus was on determining the resilience of ecologically important organisms after sudden drops in sulphide concentration and tolerance of oxygen deficiency and sulphide. Whereas in DYSMON I samples had largely been taken from natural sites, DYSMON II made use of ecological manipulation experiments (tarpaulin covers) so as to simulate natural covering with algae. A real-life experiment took place at Hiddensee in May 1995 when the effects of a very thick layer of algae were examined. This natural occurrence of an anoxic, sulphidic environment permitted a comparison with the experimentally induced anoxia in the sediments. (orig.)Das Projekt DYSMON II untersuchte, aufbauend auf den Ergebnissen von DYSMON I, die Entstehung sulfidischer, sauerstoffarmer Lebensbereiche und die darauf folgende Reaktion von Mikroorganismen und Fauna. Schwerpunkte lagen dabei auf der Ermittlung der Resilienz oekologisch wichtiger Organismen nach 'Sulfideinbruechen' und auf Untersuchungen zur Toleranz gegenueber Sauerstoffmangel und Sulfid. Waren waehrend DYSMON I ueberwiegend natuerliche Standorte beprobt worden, so konnten waehrend DYSMON II oekologische Manipulationsexperimente (Planenabdeckung) vorgenommen werden, um natuerliche Algenabdeckungen zu simulieren. Als Realexperiment gelang es, im Mai 1995 am Standort Hiddensee die Auswirkung einer sehr dicken Algenschicht zu erfassen. Diese natuerliche Entstehung von anoxischen, sulfidischen Bedingungen erlaubte einen Vergleich mit der experimentell induzierten Anoxie in den Sedimenten. (orig.)Available from TIB Hannover: F97B1291 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman
    corecore