

The Mathematical Institute Newsletter is maintained
by JanHendrik 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 February 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 email to
evertse at math.leidenuniv.nl
before January 27.
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

Bas Edixhoven gets Vicigrant
Each year, NWO allocates some Vicigrants to outstanding senior
researchers to build up a research group.
Vicigrants are financially supported by NWO,
in cooperation with the VSNU and the OCW.
Together with the Venigrants and Vidigrants for younger
researchers, they make up the
"NWOvernieuwingsimpulsprogramma" (NWOprogramme
to stimulate innovative research).
One of the Vicigrants for 2005 has been awarded to Bas Edixhoven
for his project "Arithmetic geometry, motives: computational aspects."
The research proposal can be found at
http://www.math.leidenuniv.nl/~edix/FormVICIdetail_2004.pdf.

Cooperation between general mathematics colloquia of Delft and Leiden
During the next spring, there will be a cooperation between the general
mathematics colloquia of Delft and Leiden. The intention is,
that some people from Delft will give a lecture at the colloquium in Leiden,
and that some people from Leiden will speak in Delft.
Further details will follow.

New Year's reception on Monday January 10
The annual New Year's reception of the Faculty of Sciences
is on January 10 in the entrance hall of the Gorlaeus laboratory.
The reception starts at 4:00 pm. From 3:304:00 there is a possibility
to vote for the "Discoverer of the year 2004."
During the reception, the chairman of the university board, A.W. Kist
will present the C.J. Kok prizes to the discoverers of 2004.

Stieltjes afternoon on Thursday January 13 in Tilburg
On occasion of its accession to the Stieltjes
Institute, the Universiteit van Tilburg organizes a Stieltjes
afternoon on January 13.
On this afternoon there will be lectures by Hans Schumacher, Peter Spreij,
Dolf Talman and Bas Werker. Further, the rector of the Universiteit van Tilburg
will present the Stieltjes prize for the best Ph.D. thesis in 2003
written at one of the universities participating in the Stieltjes institute.
For further information, see
http://www.tilburguniversity.nl/faculties/feb/econometrics/stieltjesafternoon.

Special day on Mathematics of Cryptology on Friday January 21 at the Lorentz Center
This is a joint meeting of the RISC Seminar of the Cryptology and Information Security group at CWI and the Intercity Number Theory Seminar.
Organizers: Ronald Cramer and Bart de Smit. Details are on the websites
http://www.cwi.nl/projects/crypto/risc.html,
http://www.math.leidenuniv.nl/~desmit/ic

Number theory lectures on Tuesday January 25 and Wednesday January 26
On January 25 and 26 there is a number theory seminar,
with lectures by
some guests from Hungary as well as some people from Leiden.
Part of the program will be a lecture by Szabolcs Tengely on January 25
at 4:00 pm in which he discusses the contents of his Ph.D. thesis.
All lectures are in room 174 of the Snellius.
The detailed program is as follows:
Tuesday January 25: 
2:00  
Ákos Pintér (Debrecen):
Applications of the binomial Thuelike equations 
3:00  
Attila Bérczes (Debrecen):
On the number of equivalence classes of binary forms with given degree
and given discriminant 
4:00  
Szabolcs Tengely:
On effective methods for Diophantine equations 

Wednesday January 26: 
2:00  
Lajos Hajdu (Debrecen):
On the problems of Turán and Szegedy concerning irreducible polynomials 
3:00  
Joost Batenburg:
On the reconstruction of crystals through discrete tomography 
4:00  
Sierk Rosema:
On the Tribonacci substitution 

Ph.D. thesis defense by Szabolcs Tengely on Thursday January 27
Szabolcs Tengely will defend his Ph.D. thesis on January 27
at 2:15 pm in the Academiegebouw, Rapenburg 73.
Title: Effective methods for Diophantine equations
Supervisor: Prof. Robert Tijdeman
Personal notes

New full professors

 Prof. Ronald Cramer in cryptology per June 1, 2004 (one day per week in Leiden,
four days per week at CWI)


 Prof. Jan Hogendijk in the history of mathematics per September 1, 2004 (one day per week)

"Jan Hogendijk studied mathematics at the University of Utrecht, with second
subject Arabic. He received his Ph. D. in Utrecht in 1983.
His dissertation was a critical edition with English translation and
commentary, of an un published tenthcentury Arabic text on conic sections.
He worked for two years at the History of Mathematics Department at
Brown University, Providence R.I., and one year at the History of Science
Department of the J.W. Goethe University in Frankfurt am Main (Germany).
Since 1986 until the present, he has
been a member of the Department of Mathematics of the
University of Utrecht. He has published extensively on the history of
the mathematical sciences between antiquity and the 17th century,
with emphasis on Islamic civilization. In September 2004 he became parttime
professor in History of Mathematics at the University of Leiden, and
adjunct professor in the Department of Mathematical Sciences of King Fahd
University of Petroleum and Minerals in Dhahran (Saudi Arabia).
See the website
http://www.math.uu.nl/people/hogend.

 Prof. Frank den Hollander in probability theory per September 1, 2004
(one day per week until October 1, 2005 after that full time)

"In the past, my research interests have been in the area of probability
theory, mathematical statistical physics and ergodic theory. In the
future, I would like to focus partly on applications of these research
areas in biology, in particular, population dynamics and genetic
evolution.
Since my PhD in Leiden (1985), I have worked at several Dutch
universities: Delft (19851991), Utrecht (19911994), Nijmegen
(19942000) and Eindhoven (20002005). Since 01/10/2000 I am
scientific director of EURANDOM, a European institute for research
in the stochastic sciences, located on the campus of TU/e. I will
step down on 01/10/2005 and move to Leiden as chair of probability.
In the past years, I have been actively involved with the strategic
development of Dutch mathematics via membership of a number of
national committees: NWO advisory board of mathematics (ACW),
Royal Academy advisory board of mathematics (ARW), board of Mathematical
Research Institute (MRI). In addition, I have been working on a
number of international committees, e.g. the Bernoulli Society Committee
of Stochastic Sciences Institutes."

New postdocs

 Dr. Robin de Jong per January 1, 2005 with Bas Edixhoven

"Being a former student at the Leiden Mathematical Institute it is a great
pleasure for me to return here, now as a postdoc student under the direction of
Bas Edixhoven. I did my PhD work at the University of Amsterdam, resulting
in my thesis entitled `Explicit Arakelov geometry'. I plan to continue to work on
explicit aspects of arithmetic algebraic geometry. In particular I plan to
continue
to work together with Bas on his project dealing
with the efficient computation of
coefficients of modular forms. During the new semester I will teach a
bachelor's course on Topology."

New Ph.D. students

 WillemJan Palenstijn per April 1, 2004 with Peter Stevenhagen en Bart de Smit


 Georgia Hadjicharalambous per May 1, 2004 with Sara van de Geer

"Dear all,
I am a PhD student of Sara van de Geer and I am also doing research with
Erik van Zwet on Estimation of OriginDestination traffic on a network.
Apart from that I am following a Master Course in
Utrecht, organized by MRI, in Stochastics in Molecular Biology."

 Johan Bosman per June 1, 2004 with Bas Edixhoven


 Michael Muskulus per August 1, 2004 with Sjoerd Verduyn Lunel en Joost Kok
(in the framework of the VIEWSproject)

"I am interested in Mathematical Biology and Natural Computing. Coming
from a thereotical physicist's background, I try to apply exact
mathematical methods to biological and computer science models, as
well as derive new mathematical results from them. My fields of interest
are centered around Dynamical Systems, especially Symbolic Dynamics,
Ergodic Theory, Probability, Differential Equations on Lattices and
Cellular Automata.
Before coming to Leiden I have been working half a year at the
Max Planck Institute for Meteorology, Hamburg, on Cyclone tracking and
statistics.
My motto is: "If I ever conceive any original idea, it will be because I
have been abnormally prone to confuse ideas... and have thus found remote
analogies and relations which others have not considered!
Others rarely make these confusions, and proceed by precise analysis."
[from KJW Craik, 'The Nature of Explanation']"

 Jeanine Daems per November 1, 2004 with Hendrik Lenstra


 Christian Svensson per February 1, 2005 with Marcel de Jeu and Sergei Silvestrov (Lund)

Guests

Guest of Bart de Smit:

 Lara Thomas: From January 528 she will visit the number theory
group to work on her Ph.D. thesis with Bart de Smit.

Guests of Rob Tijdeman:

 Attila Bérczes, Lajos Hajdu and Ákos Pintér
(Debrecen, Hungary)
will visit our institute from January 2428 on occasion of the thesis defense by Szabolcs Tengely on January 27.
On January 25 and 26 they will give some lectures (see above).
Visits/lectures outside our institute


 Peter Stevenhagen:
From January 219 he will visit David Kohel at the university
of Sydney.


 Hendrik Lenstra:
On January 16 he will give a lecture, titled "Escher,
het ultieme Droste effect" in Paradiso in Amsterdam.
This lecture is part of the "Paradisolezingen 2005,"
organized by the K.L. Poll Stichting together with
NWO and the VPRO. For further details, see
http://www.verstigt.nl/project.phtml?project=64.
