The present volume contains articles pertaining to a wide variety of sub- jects such as conformal and quasi conformal mappings and related extremal problems, Riemann surfaces, meromorphic functions, subharmonic functions, approximation and interpolation, and other questions of complex analysis. These contributions by mathematicians from allover the world express con- sideration and friendship for Albert Pfluger. They reflect the wide range of his interests. Albert Pfluger was born on 13 October 1907 in Oensingen (Kanton Solothurn) as the oldest son of a Swiss farmer. After a classical education he studied Mathematics at the ETH-Zurich. Among his teachers were Hopf, Plancherel, P6lya and Saxer. P6lya was his Ph.D. adviser. After some teaching at high schools (Gymnasien), he became professor at the University of Fribourg, and a few years later (1943) he was appointed as successor of P6lya at the ETH. He retired in 1978, but has always remained very active in research. Pfluger's lectures were highly appreciated by the students. His vivid and clear teaching stimulated and challenged them to independent thinking. Many of his Ph.D. students are now themselves teaching in universities.
His main research relates to the following fields: entire functions, Riemann surfaces, quasi conformal mappings, schlicht functions. (See list of publica- tions.) He collaborated with several mathematical colleagues, in particular with Rolf Nevanlinna, who taught parallel to him at the University of Zurich. In 1973 Pfluger was nominated foreign member of the Finnish Academy of Sciences.
1) Cross-ratios and Schwarzian derivatives in Rn.- 2) Remarks on "almost best" approximation in the complex plane.- 3) Conformal mappings onto nonoverlapping regions.- 4) On Wiener conditions for minimally thin and rarefied sets.- 5) The matrix and chordal norms of Mobius transformations.- 6) On meromorphic functions with growth conditions.- 7) A theorem of Wolff-Denjoy type.- 8) Curvature estimates for some minimal surfaces.- 9) On some elementary applications of the reflection principle to Schwarz-Christoffel integrals.- 10) Konforme Verheftung und logarithmisches Potential.- 11) On boundary correspondence for domains on the sphere.- 12) On circulants.- 13) Interpolation by entire functions in ? - another look.- 14) Moglichst konforme Spiegelung an einem Jordanbogen auf der Zahlenkugel.- 15) On BMO and the torsion function.- 16) Subharmonic majorants and some applications.- 17) On weighted extremal length of families of curves.- 18) On approximation by rational functions of class L1.- 19) On fixed points of conformal automorphisms of Riemann surfaces.- 20) The variation of harmonic differentials and their periods.- 21) On the extremality and unique extremality of certain Teichmuller mappings.- 22) Angular distribution of meromorphic functions in the unit disk.