News from the life of a mathematician...
Most of what I will publish on this page will be related to the (many)
conferences I attend and to some of the people we (my wife Anita usually
accompanies me) meet at these conferences. Maybe once in a while some other
gossip from my university and research world may filter through...
Note added on December 15, 2009:
This page (together with a few others on my website) has not been updated since my
retirement end of September 2008. This does not mean there was no news; in fact, there
was a lot which could have found its way to this page. I keep going to conferences
(check my conference page), but seemingly I do not find
the time to report on this here. The reason is simple: I have shifted most of my web-efforts
to maintaining the web presence of my
But last week I was at a conference in Leiden, and I made a lot of pictures which
I wanted to put on the web, and this in turn made me take the decision to take a new start
with this page, by adding some new stuff. So here we go...
A workshop for the 60th birthday of Henk Broer
From December 6th till December 11 I was in Leiden (The Netherlands) for a
which took place at the Lorentz Center of the university. This workshop was organized
in honour of Henk Broer by a number of his students, at the occasion of his
60th birthday. During the last decades Henk has been, together with his former
promotor Floris Takens, the driving force behind a very active group working in
the general area of dynamical systems at the University of Groningen. Personally
I have known Henk for many years, and therefore it was a real pleasure for me
to be invited to this workshop where next to attending many very interesting lectures
I also had the occasion to meet many old friends and colleagues.
Clicking on the picture of Henk at the right will take you to a gallery of
photo's which I took at the workshop.
Added on Thursday December 15, 2009
News from the time before my retirement
Jean Mawhin and Patrick Habets get 65
During the first decade of my research career I had very regular (almost weekly)
contacts with the group around Jean Mawhin at the UCL in Louvain-la-Neuve.
Although my own research differed from what was going on this group
and we never worked together on some project Jean certainly
had a big influence on my career by bringing me into contact with
many people, such as for example
Jack Hale, which then brought me to Brown University where I started
my work in bifurcation theory. It was also Jean which invited me to many
fabulous and very enjoyable meetings in Oberwolfach.
From September 10 till September 12 there was a meeting in Brussels at the occasion
of the 65th anniversary of Jean and of his close colleague Patrick Habets.
It was a very relaxed meeting which took place in the classical surroundings
of the Academy Palace in the center of Brussels. Next to some very interesting
lectures it was for me also an occasion to meet again with some people which I had not seen
for quite some time: first of all Patrick Habets, but also Jean-Pierre Gossez,
Michel Willem, Klaus Schmitt, Jaroslav Kurzweil, Stefan Schwabik, Rafael Ortega,
Fabio Zanolin, and some others.
More information on the conference can be found
Unfortunately I forgot to bring my camera, so I have no
picture gallery of the event.
Added on Saturday September 13, 2008
ICDEA 2008 in Istanbul
In succession of the ICDEA 2006 Conference in Kyoto and the
ICDEA 2007 Conference
in Lisbon this year the ICDEA 2008 took place in Istanbul, Turkey.
I went together with Anita. The conference took place at the
Beşiktaş campus of Bahçeşehir University,
a private university located at a very nice place on the European coast of the
Bosphorus. After the conference we stayed a few more days
to visit the city and also to meet with our friends Faruk and Serap who live
in the Asian part of Istanbul.
More information on the conference can be found
Clicking on the photo at the right will direct you to
a gallery with pictures we took during the conference and our touristic trips
Added on Thursday August 7, 2008
Bifurcation Workshop in Bielefeld
From last sunday (May 18, 2008) till yesterday I was in Bielefeld (Germany)
for attending a workshop on
"Bifurcations in Dynamical Systems with Applications".
This workshop fits in a series of workshops on bifurcation theory which was
started by Youri Kuznetzov in the nineties in Amsterdam and since then
took place on a two-yearly basis in places such as Gent, Utrecht, Sevilla,
Bristol, and this time Bielefeld. It was organized by Wolf-Jürgen Beyn
and Thorsten Hüls. We had a very dense program of lectures, but also a
conference dinner on tuesday evening, a trip to the
on wednesday afternoon, and a closing party at Wolf-Jürgens house on wednesday evening.
Clicking on Wolf-Jürgen's photo at the right brings you to a gallery with some of
the photo's I took during the event.
Last modified on Friday May 23, 2008
Saber Party in Laufen
Last week, from Wednesday March 12 till Monday March 17, I was in Laufen an der
Salzach, a little town in the south of Bavaria, near the Austrian border and
Salzburg. Together with Anita I was in the same place
a year ago; this year I went
alone, mainly because of the recent birth of Emma.
The occasion for going was the conference
"Progress on Difference Equations 2008"
held in honour of Saber Elaydi on the occasion of his 65th birthday.
Saber is one of the main driving forces behind the field of difference equations;
he is the president of the International Society of Difference Equations
and the editor-in-chief of the Journal of Difference Equations and Applications.
The weather was not very good, with a lot of rain and wind, so we stayed most of the
time inside the Kapuzinerhof, the old (but renovated) monastery where the event
took place. The two main social events were the reception at the own town hall
which ended with a very large number of empty wine bottles,
and the birthday dinner for Saber, with cake, music, dancing and of course again
a lot of wine. Clicking on Saber's picture at the right brings you to a
photo gallery of the event. Many more pictures are available from
Last modified on Wednesday March 26, 2008
On Wednesday March 5th, 2008, Emma was born. Emma is the daughter of our daughter Leen
and her husband Frederik, and our first grandchild. Of course this will give a lot of
changes, not only in the life of her parents, but also in our lives. With my retirement
(on October 1st of this year) in view this means that next to more time for writing
papers and travelling also more family time is waiting for us.
During the Eastern weekend I have set up a
website where you can get up to date
about what happens in Emma's daily life - just click Emma's photo at the right
to get there.
A more extensive photo gallery of Emma's first days on this world can
Last modified on Wednesday March 26, 2008
ICMC Summer Meeting in São Carlos
From January 25th till February 3rd of 2008 I was in Brazil, more precisely
at the Instituto de Ciências Matemáticas e de Computação (ICMC) in São Carlos,
where I attended the 2008 Chapter of the ICMS Summer School (in January it is
summer in Brazil!) on Differential Equations. This
summer school is held
every year, but this time there was a special edition in honour of Jack Hale
who celebrates his 80th birthday later this year. When
(after getting my PhD) I started doing research
in differential equations and dynamical systems Jack Hale was the person who
offered me to come to Brown University, where I spent one year at the
Lefschetz Center for Dynamical Systems, and where I received my
"first education" in this field. Therefore it was nice to be at this
particular meeting where I could meet Jack and his wife Hazel,
and also many other people from Jack's "entourage" which I have learned to
know over the years. The reason for having this meeting in Brazil was
the very close connection which Jack has built out over his long career
with the Brazilian mathematical community, and with the institute
in São Carlos in particular. For myself it was the second visit
to Brazil and São Carlos, after an earlier stay in 1989.
I enjoyed very much being back; clicking on Jack's photo will bring
you to a gallery of pictures from the event. You can also read more
about what happened at the meeting by clicking
Last modified on Wednesday February 6, 2008
Equadiff 2007, Vienna
The very first conference I ever attended was the Equadiff conference held in
1973 in Brussels and Louvain-la-Neuve. Since then I have been at all the "Western"
editions of this Equadiff conferences (Firenze 1978, Würzburg 1982,
Xanthi 1987, Barcelona 1991, Lisbon 1995, Berlin 1999) and I was a
co-organizer of the 2003 edition in Hasselt. Intertwined with these were
the Czechoslovak Equadiff conferences which alternate between Prague, Brno
and Bratislava; I have also attended many of these.
Last week I attended my 15th Equadiff conference, namely the
which took place in Vienna. The organisation, under the chairmanship
of Peter Szmolyan, was excellent; the only disadvantage at such conferences
is that due to the many parallel sessions it is sometimes very difficult
to choose, and almost impossible not to miss some "not-to-miss" talks.
The main social event of the conference was without doubt the conference dinner
on thursday evening which took place in the large and impressive ballroom of the
Vienna "Rathaus" (City Hall).
you can see some pictures of the event.
One of my favorites in Vienna is the
Hundertwasser house, a building
designed by the unconventional architect Friedensreich Hundertwasser. During this last stay in Vienna
I had the occasion to visit the Hundertwasser House again and to take a lot of pictures
which you can see on my
(former) dotMac Gallery.
Last modified on Friday August 17, 2007
ICDEA 2007, Lisbon
Yesterday we came home from our trip to Lisbon where I attended the
ICDEA 2007 meeting.
As usual, the meeting attracted a quite diverse selection of people and topics.
For my wife Anita and myself it was an occasion to meet some old friends and
to get acquainted with some new people. We spent most of our time with
Jean Mawhin, George Sell, Bob Sacker, Carlos Rocha and Peter Kloeden and their respective wives,
John Mallet-Paret, Roger Nussbaum, Saber Elaydi and Jim Cushing. It was also nice to meet again
with Alexandr Sharkowsky, Ondrei and Suzanna Dosly, Gerry Ladas, Michael Misiurewicz,
Hal Smith, Luis Alseda, Bob Devaney, Allan Peterson, Henrique Oliveira
(the main organiser of the conference) and a bunch of others which I forget to
mention here. The weather was nice (although sometime windy), and the social program
(with a trip to the Palace of Mafra and Cabo da Roca, a sightseeing tour through Lisbon
and two excellent dinners) was a welcome diversion from the heavy scientific program.
Our only regret was that we did not have enough time to really visit the many
beautiful spots of Lisbon, but we hope to go back in the near furure to remedy that.
At the meeting I gave - for the first time since many, many years - a talk
about Lyapunov-Schmidt reduction. I think the talk was well appreciated,
and I hope this will stimulate me to write and talk some more on this topic
which used to be my favorite when I started my research career many years ago.
On my (former) dotMac site you can find some pictures.
Last modified on Sunday July 29, 2007
Sebius' birthday party
Earlier this week we came back home from a long (three and a half weeks) trip
to Canada, more in particular to Montréal and the province of Québec.
As I explained in an earlier news item
the main reason for the trip was the
60th birthday party of Sebius Doedel and the accompanying
workshop and mini-conference organised at the Centre de Recherches Mathématiques (CRM) in Montréal.
We first spent about one week near Concordia University (the home university of Sebius), then eight
consecutive days of talks (I myself gave three talks), and afterwards one week of travelling (by car) in Québec. There were several parties at Sebius' house, and also some more official receptions
and a conference dinner. The only minor point was the weather which was very variable, with much
more rain than usual at this time of the year; this weather partly ruined our last week when we
visited Québec and the Charlevoix region.
You can read many more details about this trip on
my blog site (I tried for the first time
to make a regular report on what had happened, and this seemed to work quite well, so I may
do this more during future trips). For the moment I do not have the time to prepare some
picture galleries from our trip, because in the coming weeks I have two more conferences and talks
to prepare. However, Kurt Lust (another belgian at the meeting) did already his homework,
and you can see his pictures
Also, by clicking
here you can get some general
impressions from Montréal
(clicking the links makes a random selection, so try again if you
want to see more).
Last modified on Friday July 20, 2007
Last week I was (together with my wife Anita) at the SPT 2007 meeting, which took place in
Otranto, a small
seaside town in Puglia, at the end of the "heel" of Italy. The whole event took
place in the Grand Hotel Club Daniela, a large vacation resort away from the main city.
The isolation of the place together with the weather which was not as splendid as some
had hoped turned the conference into a real meeting place with many discussions and
exchanges of ideas. As always at the SPT meetings there was a large diversity of topics
which were addressed in the talks, but this gives of course also many opportunities
for cross pollination between different fields. More information on the scientific
part of the meeting can be found
here you can see some pictures from the
more social aspects of the conference.
Last modified on Sunday June 10, 2007
Der kleine Matroze
Those of you who meet me regularly at conferences know that in those cercles
I am kind of (im)famous for performing a German student song called
"Der kleine Matroze" ("The little sailor"). Usually this happens at one of
the evening parties, after drinking a sufficient amount of beer or wine.
I have to admit that never in my life have I been on a boat longer than a few
hours, except for about 10 days in 1976 when I was on my way to Brown
University and when together with my wife and our two year old son
we took the boat from Rotterdam to Montreal; the result: I was seriously
seasick for more than 3 days... So I can not really claim to be a man of
the sea, although once in a while I still like to sing the Matroze-song.
But as I discovered some time ago I am not the only one in our
dynamical systems community who pretends to have some sailor's blood.
To let you have some fun discovering whom this other person is I have set
up a little quiz. As you could
expect the prize will be "in natura",
i.e. bottles of wine. Unfortunately for the others the quiz is mainly directed
to people who are active in the field of dynamical systems, since you have
to more or less know the person in order to find the correct answer
to the quiz. But everybody is invited to try...