Bøger i Contemporary Mathematicians serien

We present here the mathematical papers of Hassler Whitney. We therefore include this paper, which contains personal information as well as mathematical reflections, as Whitney's own introduction to these volumes.

Among the areas which he studied are maximum principle methods and related phenomena such as Harnack's inequality, the compact support principle, dead cores and bursts, free boundary problems, phase transitions, the symmetry of solutions, boundary layer theory, singularities and fine regularity properties.

Kuo-Tsai Chen (1923-1987) is best known to the mathematics community for his work on iterated integrals and power series connections in conjunction with his research on the cohomology of loop spaces.

The mathematical works of Fritz John whose deep and original ideas have had a great influence on the development of various fields in mathema tical analysis are made available with these volumes.

Published in honor of his 70th birthday, this volume explores and celebrates the work of G.W. Stewart: Selected Works with Commentaries will appeal to graduate students, practitioners, and researchers in computational linear algebra and the history of mathematics.

When first confronted with the prospect of having my collected papers published, I felt both awe and confusion, but I calmed down when I realized that the purpose was not to honor the author, but to be of service to the mathematical community.

In a typical example it is shown that - as in gas dynamics - simple one-dimensional flow problems can be solved with the aid of shocks and simple waves.