Born 30. September 1927, Akureyri, Iceland.

Entered USA 1. August l956 on Immigration Visa (Type T-1).

- 1939-45 Gymnasium, Akureyri, Iceland
- 1945-46 School of Engineering, University of Iceland
- 1946-52 University of Copenhagen, Mag.Scient. Mathematics, Jan. l952
- 1952-54 Princeton University, Ph.D. Mathematics, June l954.

One of my hobbies is photography so some photos are included here.

- l954-56 C.L.E. Moore Instructor, MIT
- l956-57 Lecturer, Princeton University
- l957-59 Louis Block Asst. Professor, University of Chicago
- l959-60 Asst. Professor, Columbia University (on leave from MIT)
- l960-present MIT (Asst. Prof. '60-6l, Assoc. Prof. '6l-65, Prof. '65- )

- l964-66, 1974-75, 1983 (Fall) 1998 (Spring): Institute for Advanced Study, Princeton
- l970-71, 1995 (Fall) : Institute Mittag-Leffler, Sweden
- 1990 Spring: University of Copenhagen

- Gold Medal l951, University of Copenhagen, for an answer to the Mathematical Prize problem of the University. (To establish a Nevanlinna-type value distribution theory for Dirichlet series.) Incorporated in Paper No.59.
- Doctor Honoris Causa, University of Iceland, l986, University of Copenhagen, 1988, University of Uppsala, 1996.
- Børge Jessen Diplom. Award by the Danish Math. Society, Sept. l982.
- Steele Prize, American Mathematical Society 1988.
- Major Knights Cross of the Icelandic Falcon 1991. (Stórriddarakross)
- Fourier and Radon Transformations on Symmetric Spaces. Conference in honor of S. Helgason's 65 th birthday. Roskilde 1992.
- Honorary member of the Icelandic Mathematical Society, 1997.
- International Conference on Integral Geometry, Harmonic Analysis and Representation Theory, 2007. In honor of S. Helgason's 80th birthday, Reykjavik, 2007.

- Fulbright grant l952; Proctor Fellowship, Princeton University l953-54; Guggenheim Fellowship 1964-1965.
- Member, Icelandic Academy of Sciences, l960.
- Member, American Academy of Arts and Sciences, l970.
- Member, Royal Danish Academy of Sciences and Letters, l972.
- First Graduate Student Award for Teaching, MIT, 1975.
- Langvad Cultural Exchange Lectures, University of Copenhagen, June, l982.

- US participant in US-Japan Seminar in Differential Geometry, Kyoto, Japan l965.
- Principal lecturer on "Lie Groups and Symmetric Spaces" at Battelle Rencontres, l967.
- Invited lecture at International Mathematical Congress, Nice 1970.
- Invited lectures in the American Mathematical Society:
- Hour lecture, Summer Meeting, Boulder l963.
- Hour lecture, Annual Meeting, Washington l975.
- Five lectures at AMS Summer Institute, Williamstown, l972.
- Short course on Computed Tomography, Cincinnati, l982.

- Invited hour lectures at the Scandinavian Mathematical Congresses; Oslo l968, Götaborg l972, Aarhus 1980, Reykjavik, 1984.
- Series of 8 invited lectures at the University of Paris, l968.
- US representative and guest lecturer at the Danish Mathematical Society Centennial l973.
- Lecture series at Summer Schools: Seattle l967, ETH, Zürich l969, Montecatini l970, Paris l97l, Dartmouth l971, Boca-Raton l 972, Williamstown l972, Varenna l975, Montreal 1976, Oxford 1977, Reykjavik 1977, Cortona 1978, Montreal 1980, Aarhus 1980, Milano 1982, Blaubeuren 1990.
- MIT representative and guest lecturer at Technical University of Berlin Centennial (and 150th anniversary of the birth of Christoffel) Berlin l979.
- US representatative and guest lecturer at Centennial celebration of the Mathematics Seminar of the Karl Marx University of Leipzig, Leipzig l981.
- Invited lecture at Lyon Conference l984 on "The Mathematical Heritage of Élie Cartan".
- Harish-Chandra Memorial Conference, Princeton, 1984. "Operational properties of the Radon transform".
- Invited lecture at Harald Bohr Centennial Conference, Copenhagen, April 1987.
- Mathematische Gesellschaft Hamburg. 300 years anniversary 1990. Lecture on "Geometric and Analytic Properties of the Radon transform".
- Conference on occasion of Rolf Sulanke's 60 th birthday. Berlin, May 1990.
- Principal lecturer LMFK Scandinavian Congress, Reykjavík, June 1990.
- Leifur Ásgeirsson Memorial Conference, Reykjavík, Oct. 1990.
- Distinguished Lecture Series, Louisiana State University Oct. 29 - Nov. 1, 1991.
- Conference in Oslo for 150 th anniversary of the birth of Sophus Lie, August 1992.
- Conference on occasion of the 75 th anniversary of Radon's paper, September 1992.
- 2nd Gauss Symposium, München, August 1993.
- International Conference on Group Representations and Automorphic Forms, Edinburgh, 3 lectures, March 1996.
- International Conference on Analysis on Lie Groups and Partial Differential Equations, Edinburgh , June 1999.
- Conference in Leipzig: 100 years after Sophus Lie. July 1999.
- Bolyai Memorial Conference, Budapest July 2002.
- Norbert Wiener Lectures, Tufts University, October 2004.
- Invited hour lecture at the Franco-Nordic Mathematical Congress, Reykjavik, Jan. 2005.
- Invited plenary lecture at International Conference on Integral Geometry, Harmonic Analysis and Representation Theory. Reykjavik 2007.
- Invited hour lecture on Eigenspace Representations at Annual Meeting of AMS, New Orleans 2011.