Covariant technique of derivative expansion of the one-loop effective action - art. no. 105017

A simple systematic method for calculating derivative expansions of the one -loop effective action is pre sented. This method is based on using symbols of operators and well known deformation quantization theory. To demonstrat e its advantages we present several examples of application for scalar theo ry, Yang-Mills theory, and scalar electrodynamics. The superspace formulati on of the method is considered for Kahlerian and non-Kahlerian quantum corr ections for Wess-Zumino and for Heisenberg-Euler Lagrangians in super QED m odels. [S0556-2821(99)04918-8].