Heinz Klaus Strick

Heinz Klaus Strick
Name	Heinz Klaus Strick
Birth date	1938
Birth place	Cologne, Germany
Death date	2014
Death place	Bonn, Germany
Nationality	German
Fields	Mathematics, Topology, Algebraic Geometry
Institutions	University of Bonn, Max Planck Institute for Mathematics, Humboldt University of Berlin
Alma mater	University of Cologne, University of Bonn
Doctoral advisor	Friedrich Hirzebruch
Known for	Stratified Morse theory, Perverse sheaves, Intersection homology

Heinz Klaus Strick was a German mathematician noted for contributions to topology, algebraic geometry, and singularity theory. His work connected methods from algebraic topology with geometric analysis, influencing developments in stratified spaces, sheaf theory, and characteristic classes. Strick held professorships at several major German institutions and collaborated with prominent figures across Europe and North America.

Early life and education

Strick was born in Cologne and completed early schooling in Westphalia before matriculating at the University of Cologne and the University of Bonn. At Bonn he studied under Friedrich Hirzebruch, engaging with the milieu that included scholars from the Max Planck Institute for Mathematics and visitors from the Institute for Advanced Study. His doctoral dissertation built on themes related to the Hirzebruch–Riemann–Roch theorem, Chern classes, and aspects of Lefschetz fixed-point theorem, reflecting interactions with contemporaneous work by researchers at the École Normale Supérieure and the Institut des Hautes Études Scientifiques.

During graduate study Strick attended seminars that featured participants from institutions such as Princeton University, the University of Chicago, and the University of Paris (Sorbonne), exposing him to the developments of Alexander Grothendieck, Jean-Pierre Serre, and Raoul Bott. His early exposure to the research communities at the Mathematical Research Institute of Oberwolfach and the International Congress of Mathematicians influenced his orientation toward problems linking differential topology and algebraic geometry.

Academic career and positions

After receiving his doctorate, Strick took a postdoctoral position associated with the Max Planck Institute for Mathematics and served as a lecturer at the Humboldt University of Berlin. He was appointed to a professorship at the University of Bonn, where he later supervised doctoral students who went on to positions at the University of Cambridge, Harvard University, and the University of Tokyo. He held visiting appointments at the Massachusetts Institute of Technology, the University of California, Berkeley, and the Institut Henri Poincaré.

Strick participated in collaborative programs sponsored by the Deutsche Forschungsgemeinschaft and the European Research Council, and he served on editorial boards for journals affiliated with the American Mathematical Society and the London Mathematical Society. He was a regular speaker at conferences organized by the London Mathematical Society, the European Mathematical Society, and the Society for Industrial and Applied Mathematics, collaborating with researchers from the Max Planck Society and universities such as ETH Zurich and KU Leuven.

Research contributions and publications

Strick’s research concentrated on stratified spaces, perverse sheaves, and intersection homology. He developed techniques that extended ideas from Morse theory and Poincaré duality to singular varieties studied by followers of Mark Goresky and Robert MacPherson. His papers addressed the behavior of Chern–Schwartz–MacPherson classes on complex analytic spaces and refined notions of characteristic cycles introduced by researchers at the Institute for Advanced Study and the National Academy of Sciences.

He authored monographs and articles published by presses associated with the Springer-Verlag, the Cambridge University Press, and the American Mathematical Society. His work cited and built upon results of Michael Atiyah, Isadore Singer, Deligne, and Pierre Deligne, applying sheaf-theoretic methods developed in seminars at the IHES and lectures connected with the Séminaire Bourbaki. Strick contributed to the formulation of invariants for singularities resonant with concepts introduced by John Milnor and Hervé Moulin Ollagnier, and he collaborated with contemporaries at the University of Padua and the University of Bonn on joint studies of stratified Morse functions.

Prominent publications included papers on Lagrangian cycles in conormal spaces, expositions on the microlocal approach to constructible sheaves, and contributions to volumes arising from symposia at Oberwolfach and the Centre for Mathematical Sciences, Cambridge. His expository articles helped disseminate advances from the Sato School and connected to work by Masaki Kashiwara, Lê Dũng Tráng, and Bernard Teissier.

Awards and honors

Strick received recognition from German and international bodies for his research and teaching. He was awarded fellowships from the Alexander von Humboldt Foundation and received prizes from the Deutsche Mathematiker-Vereinigung for expository work. He was elected to scientific academies including the Berlin-Brandenburg Academy of Sciences and Humanities and was an invited speaker at the International Congress of Mathematicians.

He held honorary positions and visiting fellowships at institutions such as the Royal Society (UK), the Scuola Normale Superiore, and the Max Planck Society. His contributions were acknowledged at memorial sessions and special volumes produced by the European Mathematical Society and the American Mathematical Society.

Personal life and legacy

Outside mathematics Strick maintained friendships with colleagues across Europe and North America and participated in cultural institutions in Bonn and Cologne. His mentorship influenced generations of mathematicians who joined departments at the University of Bonn, the University of Göttingen, and the Technical University of Munich. Posthumous conferences and special journal issues honored his work, and his approaches to stratified spaces continue to appear in research at centers such as IHES, Princeton University, and ETH Zurich.

Strick’s legacy endures through his students and through techniques now standard in the study of singular spaces, perverse sheaves, and characteristic classes, resonating with ongoing research by scholars affiliated with the Institute for Advanced Study, the Fields Institute, and the Clay Mathematics Institute.

Category:German mathematicians Category:20th-century mathematicians Category:21st-century mathematicians