These Lecture Notes have been compiled from the material presented by
the second author in a lecture series ('Nachdiplomvorlesung') at the
Department of Mathematics of the ETH Zurich during the summer term 2002.
Concepts of 'self- adaptivity' in the numerical solution of differential
equations are discussed with emphasis on Galerkin finite element
methods. The key issues are a posteriori er- ror estimation and
automatic mesh adaptation. Besides the traditional approach of
energy-norm error control, a new duality-based technique, the Dual
Weighted Residual method (or shortly D WR method) for goal-oriented
error estimation is discussed in detail. This method aims at economical
computation of arbitrary quantities of physical interest by properly
adapting the computational mesh. This is typically required in the
design cycles of technical applications. For example, the drag
coefficient of a body immersed in a viscous flow is computed, then it is
minimized by varying certain control parameters, and finally the
stability of the resulting flow is investigated by solving an eigenvalue
problem. 'Goal-oriented' adaptivity is designed to achieve these tasks
with minimal cost. The basics of the DWR method and various of its
applications are described in the following survey articles: R.
Rannacher [114], Error control in finite element computations. In:
Proc. of Summer School Error Control and Adaptivity in Scientific
Computing (H. Bulgak and C. Zenger, eds), pp. 247-278. Kluwer Academic
Publishers, 1998. M. Braack and R. Rannacher [42], Adaptive finite
element methods for low- Mach-number flows with chemical reactions.