Lassi Päivärinta

Lassi Päivärinta is a Finnish mathematician, presently professor of applied mathematics at the department of mathematics and statistics at the University of Helsinki. Päivärinta's research is mostly in the fields of inverse problems and partial differential equations.

Education and career

Päivärinta received an MSc in mathematics at the University of Helsinki in 1976, and a PhD in mathematics in 1980. He has spent several periods at the Universities of Delaware and Washington as visiting and adjunct professor. He became professor of mathematics at the University of Oulu in 1992, and started his professorship at the University of Helsinki in 2003. He is the leader of the Finnish Centre of Excellence in Inverse Problems Research and the director of the Rolf Nevanlinna Institute and the section of applied mathematics at the University of Helsinki. He is the editor-in-chief of the journal Inverse Problem and Imaging [ [http://www.aimsciences.org/journals/ipi/ipi_online.jsp Inverse Problems and Imaging] ] .

Päivärinta was awarded the Magnus Ehrnrooth Foundation prize in mathematics by the Finnish Society of Sciences and Letters in 2006. He is a member of the Finnish Academy of Sciences.

Research

Since the late 1980's, inverse problems have attracted rapidly growing research interest, mostly in applied but also in pure mathematics. Päivärinta is one of the leading figures in this development from an early stage [Lassi Päivärinta and Erkki Somersalo: The uniqueness on the one-dimensional electromagnetic inversion with bounded potentials. Journal of Mathematical Analysis and Applications 127, 2, 1987, 312-333.] [Markku S. Lehtinen, Lassi Päivärinta and Erkki Somersalo: Linear inverse problems for generalized random variables. Inverse problem 5, 1989, 599-612.] , and his research interests range from mathematical theory to practical applications. An example of this is Alberto Calderon's inverse problem, studied by several mathematicians [Uhlmann G. (1999) Developments in inverse problems since Calderon's foundational paper, Harmonic Analysis and Partial Differential Equations: Essays in Honor of Alberto P. Calderon, (editors ME Christ and CE Kenig), University of Chicago Press, ISBN 0-226-10455-9] [Kari Astala, Matti Lassas and Lassi Päivärinta: Calderon's inverse problem for anisotropic conductivities in the plane. Comm. Partial Differential Equations 30 (2005), no. 1-3, 207-224.] and solved in the plane by Astala and Päivärinta [Kari Astala and Lassi Päivärinta: Calderon's inverse conductivity problem in the plane. Annals of Mathematics, 163, (2006), 265-299.] . The problem has immediate application in electrical impedance tomography (EIT), a means of imaging the interior of the human body. In addition to his theoretical work, Päivärinta has worked on several similar topics related with biomedical and industrial imaging. He is a founding member of the Finnish Inverse Problems Society, the world's first scientific society for inverse problems.

References

External links

* [http://math.tkk.fi/inverse-coe Finnish Centre of Excellence in Inverse Problems Research]
* [http://venda.uku.fi/research/FIPS Finnish Inverse Problems Society]