After some decades of work a satisfactory theory of quantum gravity is still not available; moreover, there are indications that the original field theoretical approach may be better suited than originally expected. There, to first approximation, one is left with the problem of quantum field theory on Lorentzian manifolds. Surprisingly, this seemingly modest approach leads to far reaching conceptual and mathematical problems and to spectacular predictions, the most famous one being the Hawking radiation of black holes. Ingredients of this approach are the formulation of quantum physics in...

Providing a systematic introduction to differential characters as introduced by Cheeger and Simons, this text describes important concepts such as fiber integration, higher dimensional holonomy, transgression, and the product structure in a geometric manner. Differential characters form a model of what is nowadays called differential cohomology, which is the mathematical structure behind the higher gauge theories in physics.

Die Herausgeber und die Autoren wollen mit dieser Festschrift den Kaufmann, Steuerberater, Wirtschaftsprufer, Vorstandsvorsitzenden der DATEV eG, Prasident des BITKOM e.V., Trager des Bundesverdienstkreuzes und vor allem den Menschen Professor Dieter Kempf ehren. Die Beitrage dieser Festschrift setzen sich in vielen Facetten und Blickwinkeln mit dem Thema Informationstechnologien als Wegbereiter fur den steuerberatenden Berufsstand auseinander. Dabei ist das Spektrum der Beitrage ahnlich wie der Wirkungskreis von Dieter Kempf sehr breit gefachert. Da allen Autoren eines gemein ist, eine...