Eine axiomatische Kennzeichnung der Determinante auf endlich-erzeugten, projektiven Moduln.
Eine Bemerkung zur Quillenschen Lösung des Serreschen Problems.
Équations linéaires dans les anneaux de polynômes
Erweiterungskriterien für stabil freie Moduln über Polynomringen.
Exact sequences of pairs in commutative rings
Extremal functions of the Nevanlinna-Pick problem and Douglas algebras
The Nevanlinna-Pick problem at the zeros of a Blaschke product B having a solution of norm smaller than one is studied. All its extremal solutions are invertible in the Douglas algebra D generated by B. If B is a finite product of sparse Blaschke products (Newman Blaschke products, Frostman Blaschke products) then so are all the extremal solutions. For a Blaschke product B a formula is given for the number C(B) such that if the NP-problem has a solution of norm smaller than C(B) then all its extremal...