The Mathematical Institute Newsletter is maintained by Jan-Hendrik Evertse. The newsletter is issued the first week of each month, except for July and August. The electronic version of the newsletter can be found on http://www.math.leidenuniv.nl/~evertse/newsletter.shtml
(go to the homepage of the Mathematical Institute and click on "Newsletter").

Copy for the January 2005 newsletter, such as announcements, personal notes, visits to conferences, guests (with place of origin and date of arrival and departure), lectures of general interest, Ph.D. thesis defenses (with title of thesis), etc. should be sent by e-mail to evertse at math.leidenuniv.nl before December 15 (!). Copy should be submitted in English plaintext, so that it can be inserted into the newsletter without time consuming typing or translating work.

Agenda and announcements

• WIMS server
   
  Since November 18 our institute has a WIMS server. Originally, WIMS stood for `Web Interactive Mathematics Server', but now that there is also grammar, geography and chemistry, it stands for `Web Interactive Multipurpose Server'. The name explains it all. This server contains a lot of interactive mathematical material, from the level of elementary school up to that of university. We can use this system for our problem sessions in calculus or linear algebra, for example. If you are interested, take a look at:

      http://wims.math.leidenuniv.nl/wims/.

  This server can also be accessed from outside the university.

  The driving force behind the WIMS project is Xiao Gang (from Nice, France). The software is free and the system falls under GNU GPL. You can also install this software at home under linux. The hardware for the Leiden mirror has been paid by Bas Edixhoven (3kE) and Joke Evers (.5kE), from what is called "derde geldstroom". The system has been installed by our system managers Martijn Feleus, Ronald Huizer, and Kristian Rietveld.

• No regular opening hours of library desk starting November 26
   
  Starting November 26, after the retirement of the librarian Cécile Tonkens-Sanchez, the desk of the library of the Mathematical Institute and the LIACS will not have regular opening hours anymore. From time to time a substitute librarian will be present for the necessary tasks in the reading room and the library systems. Further information, for instance about the new procedure for book loans, can be found on a pdf-file.

• General Colloquium lecture on Thursday December 2 by Prof. Frans Oort
   
  Prof. Frans Oort (Utrecht): Conjectures in Mathematics
  Time/place: 4:00-5:00 pm, Snellius, room 174
  Further information: http://www.math.leidenuniv.nl/~evertse/colloquium.shtml.

• Symposium in honour of the 60th birthday of Hans Metz on Thursday December 9 and Friday December 10
   
  On December 9 and 10 there will be a symposium in honour of the 60th birthday of Hans Metz, titled "Don't Panic: A functional response to Hans Metz." The symposium is held in the "Grote Collegezaal" of the Van der Klaauw laboratory, Kaiserstraat 63, Leiden.
  Further information.

• Concert on Wednesday December 15
   
  Time/place: December 15, 4:30 pm, hall of the Gorlaeus laboratory
  Performers: Kamerorkest van het Koninklijk Conservatorium under the direction of Jürgen Kussmaul
  Program: Mozart: Piano concerto No. 15, KV 450; Schubert: Symphony No. 5, D485 in B-flat Major
   
  The concert is organized by the Faculty of Creative and Performing Arts of the Universiteit Leiden, in cooperation with the Faculty of Sciences of our university and the Koninklijk Conservatorium in The Hague. The orchestra consists of advanced students of the Koninklijk Conservatorium. The solo party of the piano concerto will be played by the winner of the Super final, to be held on December 12, of the second "Nationale Pianoconcours" of the Young Pianist Foundation. Participants in this competition are all top talents aged under 25. Further information (in Dutch) can be found on an MS-word file.

• Christmas buffet dinner on Wednesday December 15
   
  The annual Christmas buffet dinner of 2004 will be on December 15 in restaurant "Het Koetshuis" at Burgsteeg 13, Leiden (near the "Burcht"). The dinner starts at 6:30 pm.
  You are kindly requested to inform Tineke Bakker-Bouma (e-mail tineke at math.leidenuniv.nl) before December 8 whether you will be at this dinner, how many people will accompany you, and whether you have special dietary wishes (e.g. vegetarian).

• General Colloquium lecture on Thursday December 16 by Dr. Vivi Rottschäfer
   
  Dr. Vivi Rottschäfer (Utrecht): Blowup solutions of the Nonlinear Schrödinger equation
  Time/place: 4:00-5:00 pm, Snellius, room 174
  Further information: http://www.math.leidenuniv.nl/~evertse/colloquium.shtml.

• Guests of Bas Edixhoven:

  - Pierre Parent (Bordeaux) and Andrei Yafaev (UCL, London) will visit our institute from December 1-3. They will each give a lecture at the geometry seminar in the afternoon of Wednesday December 1.

• Guests of Marcel de Jeu:

  - Sergei Silvestrov and Christian Svensson (Lund, Sweden) will visit our institute from December 6-8.

Visits/lectures outside our institute

- Christiaan van de Woestijne: On December 6-10 he will attend the Oberwolfach workshop "Finite Fields: Theory and Practice." Further, He is an invited speaker at the MAGMA workshop held December 11-15 at the Georg-August-Universität, Göttingen, Germany.

- Bas Edixhoven, Peter Stevenhagen: On December 10-12 they will visit Padova for work on the Erasmus Mundus Master ALGANT.

- Gerrit van Dijk: On December 13-15 he will attend the 2004 Twente conference on Lie groups.

- Bas Edixhoven: On December 15-17 he will visit Toulouse.

Technical reports

MI 2004-16

C. Bandle, L.A. Peletier, S. Stingelin: Best Sobolev constants and quasi-linear elliptic equations with critical growth on spheres.