SAM History: Overview

The precurser of the Seminar for Applied Mathematics (SAM) (in German: Seminar f¨urAngewandte Mathematik) at ETH Zurich, the Institute for Applied Mathematics (IAM) was founded on January 1, 1948, at the request of Professor (21.4.1909–25.11.1978), who had been a full profes- sor of mathematics since 1943, well known for his earlier contributions to pure mathematics. His vision was to introduce applied mathematics at ETH based on the usage of electronic computers as they were being developed in the United States, England, and the Netherlands. Among his early goals was the construction of a Swiss programmable electronic computer. As his first collaborators he hired two perma- nent assistants (30.1.1918–10.11.1970), a mathematician, and Ambros P. Speiser 13.11.1922–10.5.2003), an electrical engineer. For gathering information on the current status of computer technology, Stiefel went in October 1948 for five months on a fact finding mission to Amsterdam and sev- eral places of the United States. He also sent his two assistants for a year to the two top U.S. computer research centers: Harvard and Princeton. When Stiefel returned from the U.S., he learned that the Z4 computer, the fourth computer the ingenious German (22.6.1910–18.12.1995) had constructed during WWII had survived the war and was available for rent. He decided to rent it for a period of five years. It was installed at ETH in August 1950. Thanks to the Z4, Stiefel and his collaborators could quickly start working on numerical methods and their applications. Today we would say that in 1950 they started to work in computational science, and they were very successful in that. Their fundamental contributions to numerical algorithms are legendary: in particular, Stiefel’s conjugate gradient (CG) method (found independently also by and at the Institute for attached to UCLA in Los Angeles, CA) and Rutishauser’s quotient-difference (qd) algorithm and his LR algorithm, the predecessor of the ubiquitous QR algorithm of John G.F. Francis (England) and Vera N. Kublanovskaya (USSR). Simultaneously, under the leadership of Ambros Speiser and Heinz Rutishauser, the staff of the IAM designed and constructed in the time range 1950–1956 a much faster electronic computer, the ERMETH (Elektronische Rechenmaschine der ETH), which was operational from 1956 until 1963. Moreover, during this period Heinz Rutishauser developed the concept of a and was one of the main contributors to the groundbraking computer language ALGOL 60, and Hans-Rudolf Schwarz (*20.11.1930) wrote the first compiler for it. Heinz Rutishauser became a Privatdozent in 1951, an associate professor in 1955, and a full professor in 1962. On November 10, 1970, he died at the age of 52. Ambros P. Speiser became a Privatdozent in 1951, but in 1955 he left ETH to become the founding director of the IBM Research Laboratory in R¨uschlikon near Zurich. When he left, Peter L¨auchli and Alfred Schai were responsible for completing the ERMETH. Peter L¨auchlibecame an assistant professor in 1964 and an associate professor in 1968. In the wake of an offer from TH Munich, Heinz Rutishauser officially left the IAM in 1968 and founded, together with the promoted associate professor Peter L¨auchli(*4.6.1928) and the newly hired full professor (*15.2.1934) the Fachgruppe Computer Wissenschaften, which was upgraded into the Institut f¨urInformatik in 1974. Also in the 1960s, Eduard Stiefel gradually changed his research interest from numerical analysis to celestial mechanics, an area of wide interest at the great time of space flights. End of 1969, the Institut f¨urAngewandte Mathematik was renamed Seminar f¨urAngewandte Mathematik because Eduard Stiefel and Peter K. Henrici (13.9.1923–13.3.1987) decided to join forces. Peter Henrici had been a full professor of mathematics at ETH since 1962, and he was already a famous numerical analyst. But the rules for an institute did not allow that it was lead by two full professors who were on a par, while the rules for a seminar assumed that it had an acting director who is just primus inter pares. In spring 1970 the two groups joined and moved to the newly erected RZ building at Clausiusstrasse 55. Moreover, in December 1970, J¨urgT. Marti (*24.5.1935) came to the SAM as an associate professor; in

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1976 he was promoted to full professor. From 1974 to 1977 Rudolf E. K´alm´an (*19.5.1930), the pioneer of modern systems and control theory, was also a full professor at the SAM. (Later he held an independent professorship at the Department of Mathematics.) The research of the other professors focused on the application of group theory (Stiefel), on applied and computational complex analysis (Henrici), and on approximation theory as well as compu- tational fluid dynamics (Marti). On November 25, 1978, Eduard Stiefel died at age 69 still in office. He was later replaced by J¨urgenMoser (4.7.1928–17.12.1999), who did not join the SAM however. On March 13, 1987, Peter Henrici died at the age of 63. Unfortunately, in the 1980s, replacing first Stiefel and then also Henrici at the SAM was repeatedly delayed by the Department of Mathematics. Finally, Rolf Jeltsch (*31.10.1945) in 1989 and Randall J. LeVeque (*30.9.1955) in 1990 started their work as full professors, but LeVeque choose to return to the U.S. in 1991. Again, it took four years until he got replaced by Christoph Schwab (*14.10.1962) (assoc. prof. in 1995, full prof. in 1998). In the new century, the SAM has been strengthened further by the appointment of Ralf Hiptmaier (*10.5.1967) (assoc. prof. in 2002, full prof. in 2005) and Siddhartha Mishra (*5.5.1980) (assoc. prof. in 2012). Moreover, since 1991 the institute profitted from a number of assistant professors that were either officially or at least de facto in the SAM: Christian Lubich (08/1991–08/1992), Martin Buhmann (04/1994– 03/1997), Marcus Grote (10/1997–03/2001), Andreas Prohl (04/2002–04/2006), Manuel Torrilhon (04/2007–08/2010), Daniel Kressner (09/2008–04/2011), Siddhartha Mishra (08/2009–07/2011), Philipp Grohs (10/2011–), and Arnulf Jentzen (09/2012–). Since the 1990s the research focus of the SAM has been clearly in the numerical solution of partial differential equations, both for initial value and boundary value problems. Some of the assistant professors and some of the permanent scientific staff have been engaged in other areas.

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