Abstract We present a new group-theoretical technique to calculate weak field expansions for some Feynman diagrams using invariant polynomials of the dihedral group. In particular we show results obtained for the first coefficients of the three loop effective lagrangian of 1 + 1 QED in an external constant…
Wir verwenden den Weltlinienformalismus und die Weltliniennumerik zur Berechnung von lokalen Operatoren. Insbesondere berechnen wir den Energieimpulstensor eines quantisierten Skalarfeldes, welches Dirichlet Randbedingungen unterliegt. Der Weltlinienformalismus bildet Amplituden einer Quantenfeldtheorie…
Psychosoziale Belastung ist ein vielfach belegter Risikofaktor für ein negatives chirurgisches Outcome nach kardiochirurgischen Operationen. Wenig untersucht ist der Einfluss von präoperativ erhobenen demographischen, sozialen und somatischen Faktoren auf die Ausprägung der psychischen Belastung prä-…
Behavioral (e.g. consumption) patterns of boundedly rational agents can lead these agents into learning dynamics that appear to be "wasteful" in terms of well-being or welfare. Within settings displaying preference endogeneity, it is however still unclear how to conceptualize well-being. This paper contributes…
Normative reasoning in welfare economics and social contract theory usually presumes
invariable, context-independent individual preferences. Following recent work particularly
in behavioral economics this assumption is difficult to defend. This paper therefore explores
what can be said about preferences…
Economic change, while creating innovation and growth, at the same time generates "gales of creative destruction". It is still largely unclear what this concept implies for the task of assessing welfare (and, correspondingly, the need for and scope of policy-making) in a novelty-generating, knowledge-based…
According to the advocates of a "Generalized Darwinism" (GD), the three core Darwinian principles of variation, selection and retention (or inheritance) can be used as a general framework for the development of theories explaining evolutionary processes in the socioÿeconomic domain. Even though these…
Schumpeter's and Hayek's view of market coordination as being not about efficiency, but about endogenous change and never-ending discovery has been increasingly recognized even by the mainstream of economics. Underlying this view is the notion of creative learning agents who bring about novelty. We argue…
Die Implantation einer hohen Dosis Ge-Ionen in Siliziumkarbid und nachfolgende Temperung führt unter bestimmten Bedingungen zur Formierung von Ge-reichen kristallinen Ausscheidungen mit Abmessungen im Nanometerbereich. Solche Nanokristalle sind von besonderem Interesse für Anwendungen in der Optoelektronik.…