CV and list of publications for Trygve Johnsen

**Born**: December 29, 1956

**Nationality**: Norwegian

**Present position**: Professor of pure mathematics,
Department of Mathematics and Statistics, University of Tromsø (UiT), Norway.

Cand.real.(Master)-exam (U of O) with specialization in pure mathematics, December 1981.

Pedagogisk seminar in Oslo (Course in Pedagogics), spring 1982.

Dr.scient.(Ph.D)-degree in mathematics at the University of Oslo, August 1984.

Military service, Norwegian army, Kongsberg/Kirkenes Jan. 1976 - Jan. 1977.

Part time teaching assistant at the Univ. of Oslo, autumn 1980, and all of 1981.

NAVF scholarship in mathematics, Aug. 1 - Dec. 31, 1982, University of Oslo.

Scientific assistant at the University of Oslo, Jan. 1, 1983 - July 31, 1987.

Førsteamanuensis (Associate Professor) in pure mathematics at the University of Tromsø, Norway Aug. 1, 1987 - Dec. 31, 1994 (Professor from May 1, 1994).

Professor of pure mathematics at the University of Bergen Jan. 1, 1995 - Dec. 31, 2007.

Professor II at the Univ. of Tromsø, July 1, 1995 - Dec 31, 1999.

Head of Dept. for Math. and Statistics, Univ. of Tromsø, Aug. 1, 2009 - Dec. 31, 2017.

Professor of pure math. at the UiT, Jan. 1, 2008 - July 31, 2009, and Jan. 1, 2018 -->.

Paid leave 1/8-84-31/7-85. Visiting Scholar at M.I.T., Cambridge, Mass., USA.

Unpaid leave 1/9-31/12-86. Scholarship holder at Institut Mittag-Leffler, Sweden.

Paid leave 1/1-31/7-90. Visiting Scholar at Brandeis University, Mass., USA.

Paid leave 1/1-31/7-93. Visiting Scholar at M.I.T., Cambridge, Mass., USA.

Paid leave 30/9-3/11-96. Visiting scientist at Institut Mittag-Leffler, Sweden.

Paid leave 1/1-31/7-00. Visiting Scholar at University of Utah, Salt Lake City, USA.

Paid leave 1/8-19/12-00. Visitor at MPIM, Bonn, Germany.

Paid leave 1/9-11/12-04. Visitor at Aarhus University, Århus, Denmark.

Paid leave 26/4-15/6-11. Visiting scientist at Institut Mittag-Leffler, Sweden.

Paid leave 1/4-30/6-15. Visitor at IMPA, Rio de Janeiro, Brazil.

I have accepted to be visiting professor at IIT Bombay, September-December 2018.

- Leader for the Section for Mathematics and Statistics at the University of Tromsø, 1/8-88-31/7-89.
- Leader for the local branch, NTL-93, at the University of Tromsø, of the Norwegian Civil Service Union 14/3-91-31/12-92.
- Elected leader of the group for pure mathematics at the Dept. of Mathematics, University of Bergen, 1/1-02-31/7-05. Member of the inofficial consultative leader group at that institute Sept. 2003 - July 2005.
- Leader of the council for educational matters at Dept. of Mathematics, University of Bergen 1/1-96-31/12-98.
- Deputy coordinator for the Nordic algebraic geometry network NORDAG 2000-05.
- Leader of "Programstyret for lektorutdanninga i realfag", UiT, since 2011. Head of Department for Mathematics and Statistics, Univ. of Tromsø, Aug. 1, 2009 - Dec. 31, 2017.

- national committee "for promotion to full professor in mathematics", 2008-10.
- 15 external hiring committees at universities or colleges, 8 of them since 2006.
- 11 doctoral committees (5 times opponent and 6 times as adm. leader).
- "Det faglige rådet" for the Norwegian Mathematics Center, Trondheim, 2012-13.
- the board of the Norwegian Mathematical Society 2009-2013, and chairman of the electoral committee for Norsk matematikkråd 2010-2013.

I have been/given:

- reviewed 70 articles for MatSciNet, Mathematical Reviews,
- referee for Finite Fields and their Applications, Mathematica Scandinavica, Designs, Codes and Cryptographty,
IEEE Trans. of Info. Theory, Quarterly Journal of Mathematics, Arkiv før matematik, Sarajevo Journal of Mathematics,
Applicable Algebra in Engineering, Communication and Computing, Compositio Mathematica, Acta Mathematica, Osaka Journal of Mathematics, Pacific Journal of Mathematics, Cryptography and Communications.
- one of four/five organizers of the summer schools at the Sophus Lie Center, Nordfjordeid, 2007-2017, one of three organizers of the Abel Symposium, Voss, 2009.
- invited lectures at the EMS Mathematical Week-end, Copenhagen, 2008, as a presentation of Dan Laksov as an honorary doctor at the Univ. of Bergen, 2008, at the 60'th anniversary of the Dept. of Math., Univ. of Bergen, 2009, at the 12 ALGA meeting, IMPA, Rio de Janeiro, 2012, at the annual meeting of Norsk matematikkråd 2013, and at the AGCT, India, conference in Mumbai 2013. I also gave talks at Univ.of Oslo, Ghent Univ., Belgium, and Tahiti, French Polynesia (in 2006-7), at the Norwegian National Algebra seminars in 2008, 2010, 2013, at the Norwegian Cryptology seminars in 2008 and 2009, at the Institut Mittag-Leffler, Sweden, in 2011, and at the Norcom, Stockholm 2013, and Levi 2016, and Asgard conferences, Oslo, 2016 and 2017, and at 5th Castle meeting in Coding Theory, Estonia, August 2017.
- leader or deputy leader for the Norwegian teams, International Mathematics Olympiad in 1989, 1991, 1992, 2003.
- programsensor for master studies in pure mathematics at UiB 2011-13.
- programsensor for "`Lektorutdanning, realfag" and "Erfaringsbasert master i matematikk" at UiB 2015-17.
- project leader for Research institution-based strategic project ISP-MATEMATIKK that was granted from RCN in 2014
- confirmed that I will act as a Visiting Honorary Professor at The Department of Mathematics, IIT Bombay during the fall 2018.
- in the scientific committee of the 2018 CIMPA Research School - Latinamerica: "Commutative Algebra with Applications to Statistics and Coding Theory", June 25 - July 6, 2018, Zacatecas, Mexico, where I will give a series of lectures.

**Master students:**

I have supervised 22 master/cand.scient. students in pure mathematics, and co-supervised 8 students in the didactics of mathematics.

Single supervisor for Andreas L. Knutsen, Dr.Sci., UiB, 2001

Co-supervisor for H.G.Schaathun, Dr.Sci.informatics, UiB, 2002.

Single supervisor for Gert Hana, Ph.D, UiB, 2006.

Main supervisor Aug. 2006 - Dec. 2007, and co-supervisor Jan. 2008 - Sept. 2010, for

Nils Henry Rasmussen, Ph.D., UiB, 2010.

Main supervisor 2011 - 2013, co-supervisor 2013-15, for Jan Roksvold, Ph.D., UiT, 2015.

1) "A classification of covariants and contravariants for plane cubics". Preprint, Universitety of Oslo, 1982.

2) "The singularities of the 3-secant curve associated to a space curve", Transactions of the American Math. Society, Vol. 285, No 1, pp. 107-118, 1986.

3) "Multiplicities of solutions to some enumerative contact problems", Mathematica Scandinavica, Vol. 63, pp. 87-108, 1988.

4) "Local properties of secant varieties in symmetric products. Part I"(with Mark E. Huibregtse), Transactions of the AMS, Vol. 313, No 1, pp. 187-204, 1989.

5) "Local properties of secant varieties in symmetric products. Part II", Transactions of the American Math.Society, Vol. 313, No 1, pp. 205-220, 1989.

6) "Local multiplicities of tangential trisecants to a space curve". In "Enumerative Geometry, Proceedings, Sitges 1987", LNM, Springer Verlag, Vol. 1436, p. 77-100, 1989.

7) "Secant lines to projective curves; an infinitesimal study of the symmetric products" (with M. Coppens), "Enumerative Algebraic Geometry. Proceedings of the 1989 Zeuthen symposium", Contempory Mathematics, Vol. 123, pp. 61-87, 1991.

8) "Eight-secant conics for space curves", Math. Z., Vol. 211, pp. 609-626, 1992.

9) "A Determination of the Parameters of a large class of Goppa codes", with N. Monzavi og S. Manshadi, IEEE Trans. Info.Theory, Vol. 40, No.5, pp. 1678-1681, 1994

10) "Rational curves of degree at most 9 on a general quintic threefold" (with Steven Kleiman), Communications in Algebra, Vol 24(8), pp. 2721-2753, 1996.

11) Appendix to "An infinitesimal study of secant space divisors" by Marc Coppens, Journal of pure and applied algebra, 113, Appendix on pp. 139-144, 1996.

12) "Plane projections of space curves", In "Parameter spaces", Banach Center Publ., Vol. 36, Institute of Mathematics, Polish Acad.of Sci., pp. 89-110, Warszawa 1996.

13) "Toward Clemens' conjecture in degrees between 10 and 24" (with Steven Kleiman), Serdica Mathematical Journal, Vol. 23. pp. 131-142, 1997.

14) "Isolated rational curves on K3-fibered Calabi-Yau threefolds" (w. T. Ekedahl and D.E. Sommervoll), Manuscripta Mathematica, Vol. 99, pp. 111-133, 1999.

15) "Rank two bundles on Algebraic Curves and Decoding of Goppa Codes", International Journal for Pure and Applied Mathematics, Vol. 4, No. 1, pp. 33-45, 2003.

16) "Rational Curves in Calabi-Yau threefolds", 35 pages (w. A.L. Knutsen), Communications in Algebra, Vol. 31(8), 2003.

17) " projective models in scrolls", (Book, 164 pages, with A.L. Knutsen), Springer Lecture Notes in Mathematics, No. 1842, 2004.

18) ``Schubert Unions in Grassmann Varieties'', with Johan P. Hansen and Kristian Ranestad, Finite Fields and its Application, Vol. 13, pp. 738-750, 2007.

19) ``Scroll Codes'', with Gert Hana, Des. Codes and Crypt., Vol. 45, p. 365-377, 2007.

20) ``Decoding of Scroll Codes'', with George H. Hitching, In "Algebraic Geometry and its Applications"', ISBN 978-981-279-342-3, Vol. 5 of "Series on Number Theory and its Applications", World Scientific, Vol. 45, pp. 365-377, 2008.

21) "Rational curves on a general heptic fourfold", with Gert Hana, Bull. Belg. Math. Soc. Simon Stevin Volume 16, Number 5, 861-885, 2009

22) ``Grassmann Codes and Schubert unions'', with Johan P. Hansen and Kristian Ranestad, Seminaires et Congres, Paris: Soc. Mat., France, Vol. 21, pp. 103-123, 2010.

23) "Scroll codes over curves of higher genus", with N. H. Rasmussen, Applicable Algebra in Engineering, Communication and Computing, Volume 21, Number 5, 397-415, 2010.

24) "Higher weights of Grassmann codes in terms of properties of Schubert unions", with Sudhir Ghorpade, Arunkumar R. Patil, Harish K. Pillai, arXiv:1105.0587, 2011.

25) "Wei-type duality Theorems for matroids", with Thomas Britz, Dillon Mayhew, Keisuke Shiromoto, Des. Codes Cryptography 62, No. 3, 331-41, 2012.

26) "Hamming weights and Betti numbers of Stanley-Reisner rings associated to matroids", with Hugues Verdure, Applicable Algebra in Engineering, Communication and Computing, Volume 24, Issue 1, p.73-93, January 2013.

27) "Stanley-Reisner resolutions of constant weight linear codes", with Hugues Verdure, Designs, Codes and Cryptography, 72, No. 2., pp. 471 - 481, 2014.

28) "Betti numbers associated to the facet ideal of a matroid", with Jan N. Roksvold and Hugues Verdure, Bulletin of the Brazilian Mathematical Society, 45, No.4, pp. 727 - 744, 2014.

29) "Chains, Demi-matroids, and Profiles", with Thomas Britz and James Martin, IEEE Transactions on Information theory, Volume 60(2), p. 986-981, 2014.

30) "Generalized weight polynomials of matroids", with Jan N. Roksvold and Hugues Verdure, Discrete Mathematics, 339, No. 2, pp. 632-645, 2016.

31) "A generalization of Kung's bound", with Keisuke Shiromoto and Hugues Verdure, Designs, Codes and Cryptography, 81, No. 1, pp. 169-78, 2016

32) "Generalized Hamming weights for almost affine codes", with Hugues Verdure, IEEE Transactions on Information Theory, 63, No. 4, pp. 1941-53, 2017.

33) "Relative Hamming weights and extended weight polynomials of almost affine codes", with Hugues Verdure, Coding Theory and its applications, 5th International Castle Meeting, ICMCTA 2017 Proceedings, LNCS 10495 (Springer Lecture Notes in Computer Science), pp. 207-16, 2017.

34) "Flags of Almost Affine Codes", with Hugues Verdure, Des. Codes Cryptogr.,

https://doi.org/10.1007/s10623-017-0438-1, 2017.

35) "Relative profiles and extended weight polynomials of almost affine codes", submitted to a journal.

hugues 2018-01-26