4èmes Journées Approximation
International conference on constructive complex approximation
Thursday June 28 and Friday June 29, 2012
Salle de Réunion, Bâtiment M2

Laboratoire Paul Painlevé UMR 8524
Université de Lille 1, FRANCE



The aim of this meeting, the fourth one after similar meetings in 2000, 2004, and 2008, is to bring together people interested in complex approximation theory from France and Belgium, but also from other places.

Subjects covered by the 2012 meeting include : orthogonal polynomials and orthogonal rational functions, Hermite-Padé and rational approximation, numerical approximation, potential theory, analytic function spaces, inverse elliptic problems, random matrices, quadrature formulas...


The meeting will take place between Thursday 9h30 and Friday 18h00. It consists of seven one-hour invited talks, a limited number of 30-minutes contributed talks and a poster session. Please let us know as soon as possible and before April 30 if you want to give a talk/poster.

9h30 - 10h00 Welcome of participants
10h00 - 10h50 Norman Levenberg (Dept. Mathematics, Indiana University, Bloomington): "Large deviation in certain vector energy settings"
11h00 - 11h50 Alexander Borichev (Laboratoire d’Analyse, Topologie, Probabilités UMR, Université d'Aix-Marseille): "Two completeness problems in the Paley-Wiener space"
12h00 - 13h45 Lunch (Restaurant universitaire Charles Barrois)
14h00 - 14h50 Nick Trefethen (Mathematical Institute, University of Oxford): "Highlights of ATAP"
15h00 - 15h50 Marc Van Barel (Department of Computer Science, Katholieke Universiteit Leuven): "Orthogonal functions and inverse eigenvalue problems"
16h00 - 16h30 Coffee break and Poster session(*)
16h30 - 17h00 Lun Zhang (KU Leuven): ""Ladder operators and differential equations for multiple orthogonal polynomials"
17h00 - 17h30 Maksym Derevyagin (TU Berlin): "From CMV matrices to Jacobi matrices"
17h30 - 18h00 Abey Lopez (KU Leuven) : "Multiple orthogonal polynomials arising in the normal matrix model with a quartic potential"
9h00 - 9h50 Guillermo Lopez-Lagomasino (Universidad Carlos III, Madrid): "Direct and inverse results on the convergence of row sequences of Hermite-Padé approximation"
10h00 - 10h30 Coffee break
10h30 - 11h00 Stanislas Kupin (Universite Bordeaux 1): "On the growth of the polynomial entropy integrals for measures from the Szeg\H{o} class"
11h00 - 11h30 Miroslav Pranic (University of Banja Luka): "Recurrence relations for orthogonal rational functions"
11h30 - 12h00 Mirta Castro Smirnova (Universidad de Sevilla): "On a paper by Karlin and McGregor".
12h00 - 13h45 Lunch (Restaurant universitaire Charles Barrois)
14h00 - 14h50 Juliette Leblond (APICS, INRIA Sophia Antipolis): "Best approximation in generalized Hardy classes, application to inverse problems for elliptic PDE"
15h00 - 15h50 Tom Claeys (Institut de Recherche en Mathématique et physique, Université Catholique de Louvain): "Random matrices with equi-spaced external source"
16h00 - 16h30 Coffee break and Poster session(*)
16h30 - 17h00 Mohamed Jalel Atia (Faculté des Sciences de Gabes): "An explicit formula for the linearization coefficients of Bessel polynomials II"
17h00 - 17h30 Ana Filipa Loureiro (Centro de Matemática da Universidade do Porto) "The Kontorovich-Lebedev transform as a map between d-orthogonal polynomials".
17h30 - 18h00 Amílcar Branquinho (Universidade do Coimbra) "On the full Kostant Toda system and the discrete Korteweg de Vries equations".
(*) Posters presented by:


The workshop takes place at the Université de Lille 1, Salle de Réunion, Bâtiment M2 (first floor), Cité Scientifique, Villeneuve d'Ascq, in the north of France. This lecture hall is located in the main building M2 of the department of mathematics. Some useful links


There is no inscription fee, but registration before Mai 31 is mandatory, please use the following form. The update of the list of participants will be done manually on a regular basis. There will be a limited number of 30-minutes contributed talks and a poster session. Please let us know as soon as possible and before April 30 if you want to give a talk/poster.

We have reserved 10 rooms in the following hotel

until Mai 30. This hotel is close to the railway station Lille Flandres, with metro connections to the university. For a room, please contact directly the hotel and mention "ja2012, University of Lille" at your reservation. Some other hotels which are in the same areay for about the same price (but without prereservation):

We have also listed two AppartHotels which propose rooms for 1-4 people, without breakfirst but with small citchen. They are also downtown Lille, but a bit further away from the railway stations. If you want to search for a hotel yourself.


On Thursday June 28, 2012 at 8pm, the conference dinner will take place at the restaurant Brasserie Flore, This restaurant is located in downtown Lille close to the "Grande place", metro station Rihour (and 300 meters from the railway station Lille Flandres). The dinner is a priori non vegetarien, please write us in case of special needs.

Some other events for those staying more time in Lille:


We kindly acknowledge support from the
  • Laboratoire Paul Painlevé UMR 8524 (Université Lille 1 - CNRS)
  • Painleve  CNRS
  • Laboratoire de Mathématiques Pures et Appliquées Joseph Liouville (Université Littoral - CNRS)
  • Fédération de Recherche Mathématique du Nord Pas de Calais
  • ANR project FRAB
  • Université Lille 1 - Sciences et Technologies
  • USTL
  • SMAI-SIGMA - interest group of the french mathematical society of applied mathematics
  • SMAI


    Bernhard Beckermann (Labo Painlevé, Lille), Ana C. Matos (Labo Painlevé, Lille), Ahmed Salam (LMPA, Calais), Franck Wielonsky (LATP, Marseille).


  • Approximation Days 2012 at KU Leuven on July 2-3, 2012.

  • BB (bbecker@math.univ-lille1.fr), June 14, 2012