Bertil Gustafsson (born 1939) is a Swedish applied mathematician and

numerical analyst Numerical may refer to: * Number * Numerical digit * Numerical analysis Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic computation, symbolic manipulations) for the problems of mathematical ...

. He is currently a Professor emeritus in the Department of Information Technology at

Uppsala University Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation. Initially fou ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. Gustafsson is known for his work in

numerical methods Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods t ...

for time-dependent

partial differential equation In mathematics, a partial differential equation (PDE) is an equation which involves a multivariable function and one or more of its partial derivatives. The function is often thought of as an "unknown" that solves the equation, similar to ho ...

s and its applications in

fluid dynamics In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in motion ...

. He is the G in GKS (Gustafsson– Kreiss–Sundstrom) theory for initial-boundary value problems which discusses the stability criterion for numerical approximations of initial–boundary value problems. Gustafsson has also authored a couple of books on the topic numerical methods applied to PDE.

Education and career

Gustafsson attended senior high school in

Norrköping Norrköping ( , ) is a city in the province of Östergötland in eastern Sweden and the seat of Norrköping Municipality, Östergötland County, about 160 km southwest of the national capital Stockholm, 40 km east of county seat Lin ...

, a city in Sweden. In 1962, he joined Uppsala University, where there was a tradition of prominent mathematicians, including

Arne Beurling Arne Carl-August Beurling (3 February 1905 – 20 November 1986) was a Sweden, Swedish mathematician and professor of mathematics at Uppsala University (1937–1954) and later at the Institute for Advanced Study in Princeton, New Jersey. Beurling ...

and

Lennart Carleson Lennart Axel Edvard Carleson (born 18 March 1928) is a Swedish mathematician, known as a leader in the field of harmonic analysis. One of his most noted accomplishments is his proof of Lusin's conjecture. He was awarded the Abel Prize in 200 ...

. At Uppsala, Gustafsson developed a strong preference for applied mathematics and when he was in his second year,

Heinz-Otto Kreiss Heinz-Otto Kreiss (14 September 1930 – 16 December 2015) was a German mathematician in the fields of numerical analysis, applied mathematics, and what was the new area of computing in the early 1960s. Born in Hamburg, Germany, he earned his Ph.D ...

joined Uppsala University. It was Kreiss who introduced young Gustafsson to

numerical analysis Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic computation, symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of ...

, and the then new field of

computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, hardware and softw ...

. In 1971, Gustafsson received his Ph.D. degree under the supervision of Kreiss. His dissertation was on difference methods for hyperbolic equations. Gustafsson has continued to pursue numerical methods in differential equations for most of his career, and much of his early work consisted of applying his theoretical developments to practical problems. These included

weather prediction Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the ...

, both in Sweden and at the

National Center for Atmospheric Research The US National Center for Atmospheric Research (NCAR ) is a US federally funded research and development center (FFRDC) managed by the nonprofit University Corporation for Atmospheric Research (UCAR) and funded by the National Science Foundat ...

based in

Boulder, Colorado Boulder is a List of municipalities in Colorado#Home rule municipality, home rule city in Boulder County, Colorado, United States, and its county seat. With a population of 108,250 at the 2020 United States census, 2020 census, it is the most ...

. In 2002, he was elected a member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

Books

*High Order Difference Methods for Time Dependent PDE, Springer-Verlag (2008). *Time Dependent Problems and Difference Methods, with

and Joseph Oliger, John Wiley (1995).

References

External links

* {{DEFAULTSORT:Gustafsson, Bertil Living people 1939 births Academic staff of Uppsala University Uppsala University alumni Members of the Royal Swedish Academy of Sciences 20th-century Swedish mathematicians