Djalil CHAFAÏ (شاﻓﻌﻲ جلیل)
Professeur des universités. Mathématiques et leurs applications.
Université Paris-Est Marne-la-Vallée (UPE-MLV)
Main research interests:
- Markov processes/semigroups, their equilibrium/geometry
- Sobolev type inequalities and partial differential equations
- Gauss analysis, concentration of measure, isoperimetry
- Stochastic models and stochastic inverse problems
- Mathematical Biology (pharmacology, biostatistics)
- Mathematical Physics (spin systems, statistical mechanics)
- Computer Science (data streams processing, queuing)
- Earth Science (variational assimilation in meteorology)
- High dimensional probability and statistics, convexity
- Random matrices, random graphs, and random projections
- Boltzmann-Shannon entropy, information theory
- Random structures and algorithms, stochastic simulation
I am currently working on making coffee without breaking the teapot (weak breakfast conjecture).
Scientific life in Marne-la-Vallée:
Other activities:
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Bordenave, Ch.
and
Caputo, P.
and
Chafaï, D.
Spectrum of large random reversible Markov chains - heavy-tailed weights on the complete graph
Preprint, submitted (2009)
arXiv ·
HAL
-
Chafaï, D.
and
Malrieu, F.
and
Paroux, K.
On the long time behavior of the TCP window size process
To appear in Stochastic Processes and their Applications (2009)
arXiv ·
HAL
-
Bordenave, Ch.
and
Caputo, P.
and
Chafaï, D.
Spectrum of large random reversible Markov chains: two examples
Preprint, in revision for
ALEA (2010)
arXiv ·
HAL
-
Cattiaux, P.
and
Chafaï, D.
and
Motsch, S.
Asymptotic analysis and diffusion limit of the Persistent Turning Walker Model
To appear in Asymptotic Analysis (2009)
arXiv ·
HAL
-
Chafaï, D.
and
Malrieu, F.
On fine properties of mixtures with respect to concentration of measure and Sobolev type inequalities
Annales de l'Institut Henri Poincaré (B) Probabilités et Statistiques 46, 72-96 (2010)
arXiv ·
HAL · DOI
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Chafaï, D. and Concordet, D.
Confidence regions for the multinomial parameter with small sample size
Journal of the American Statistical Association 104, 1071-1079 (2009)
arXiv ·
HAL · DOI
-
Chafaï, D.
Aspects of large random Markov kernels
Stochastics 81, 415-429 (2009)
DOI
-
Bakry, D.
and
Baudoin, F.
and
Bonnefont, M.
and
Chafaï, D.
On gradient bounds for the heat kernel on the Heisenberg group
Journal of Functional Analysis 255, 1905-1938 (2008)
arXiv ·
HAL ·
MSN ·
DOI
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Antic, J.
and
Laffont, C.
and
Chafaï, D.
and
Concordet, D.
Comparison of nonparametric methods in nonlinear mixed effects models
Computational Statistics and Data Analysis 53, 642-656 (2009)
Special issue on Computational and clinical trials
HAL ·
DOI
- Chafaï, D.
Circular law for non-central random matrices
Preprint, submitted (2007)
arXiv ·
HAL
- Chafaï, D.
The Dirichlet Markov Ensemble
Journal of Multivariate Analysis 101, 555-567 (2010)
arXiv ·
HAL · DOI
- Chafaï, D.
and
Concordet, D.
Explicit formulas for a continuous stochastic maturation model:
Application to anticancer drug pharmacokinetics/pharmacodynamics
Stochastic Models 24, 376-400 (2008)
arXiv ·
HAL ·
MSN ·
DOI
- Chafaï, D.
and
Concordet, D.
A new method for the estimation of variance matrix with prescribed zeros in nonlinear mixed effects models
Statistics and Computing 19, 129-138 (2009)
arXiv ·
HAL ·
DOI
-
Chafaï, D.
and
Concordet, D.
On the strong consistency of asymptotic M-estimators
Journal of Statistical Planning and Inference 137, 2774-2783 (2007)
arXiv ·
HAL ·
MSN ·
DOI
- Chafaï, D.
Binomial-Poisson entropic inequalities and the M/M/∞ queue
ESAIM Probability and Statistics 10, 317-339 (2006)
arXiv ·
HAL ·
MSN ·
DOI ·
Numdam
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Chafaï, D. and
Loubes, J.-M.
On nonparametric maximum likelihood for a class of stochastic inverse
problems
Statistics & Probability Letters 76, 1225-1237 (2006)
arXiv ·
HAL ·
MSN ·
DOI
- Chafaï, D.
Entropies, Convexity, and Functional Inequalities -
On Φ-entropies and Φ-Sobolev inequalities
Journal of Mathematics of Kyoto University 44, 325-363 (2004)
arXiv ·
HAL ·
MSN · Project-Euclid
- Chafaï, D.
Glauber versus Kawasaki for spectral gap and
log-Sobolev inequalities of some unbounded conservative spin
systems
Markov Processes and Related Fields 9, 341-362 (2003)
arXiv ·
HAL ·
MSN
- Chafaï, D.
Gaussian maximum of entropy and reversed
logarithmic Sobolev inequality
Séminaire de Probabilités XXXVI,
Lecture Notes in Mathematics 1801, 194-200 (2002)
arXiv ·
HAL ·
MSN ·
DOI ·
Numdam
- Rabier, F.
and
Fourrié, N.
and
Chafaï, D. and
Prunet, P.
Channel selection methods for infrared
atmospheric sounding interferometer radiances
Quarterly Journal of The Royal Meteorological Society 128, 1011-1027 (2002)
PDF ·
DOI ·
this journal is not indexed by the Mathematical Reviews
- Chafaï, D. and
Ledoux, M.
Méthodes fonctionnelles pour des grandes déviations
quasi-gaussiennes (in French)
Comptes Rendus à l'Académie des Sciences Paris 329, 523-526 (1999)
PDF ·
MSN ·
DOI
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Ané, C. and
Blachère, S. and
Chafaï, D. and
Fougères, P. and
Gentil, I. and
Malrieu, F. and
Roberto, C. and
Scheffer, G.
Sur les inégalités de Sobolev logarithmiques (in French)
Panoramas et Synthèses 10,
Société Mathématique de France, Paris
(2000) xvi+217p.
The following documents are (un)published in the
prestigious Journal of
Unpublished Results. More seriously, and more precisely, these notes were never
submitted for publication.
-
Chafaï, D.
Behavior of the extremal singular values of random matrices
Fall school on Interactions between compressed sensing, random matrices, and high dimensional geometry
Unpublished lecture notes (2009)
[PDF]
-
Chafaï, D.
Circular Law Theorem for Random Markov Matrices
Unpublished notes (2008)
[arXiv ·
HAL]
-
Chafaï, D.
Random projections, marginals, and moments
Unpublished notes (2007)
[PDF]
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Chafaï, D. and Concordet, D.
Covariance matrices with prescribed null entries
Unpublished notes (2006)
[PDF]
-
Chafaï, D.
Inégalités de Poincaré et de Gross pour les mesures de
Bernoulli, de Poisson, et de Gauss (in French)
Unpublished notes
(2005) [HAL]
-
Chafaï, D.
An elementary proof of some functional inequalities on paths space for
Lévy processes by a cylindrical method
Unpublished notes (2002) [PDF]
-
Chafaï, D. and Malrieu, F.
A note on functional inequalities for some Lévy processes
Unpublished notes (2002) [PDF]
For
some extensions of this work, see the papers:
-
Chafaï, D.
Mémoire de doctorat (2002) and Mémoire d'habilitation à diriger des recherches (2008)
Working seminars notes (in French)
-
Chafaï, D.
Dimension d'entropie, d'après Guionnet and Shlyakhtenko
Rough talk notes (2008) [PDF]
-
Chafaï, D.
Sur certaines mesures produit conditionnées
Rough talk notes (2005) [PDF]
-
Chafaï, D.
Covariance de modèles d'interface et marches aléatoires
en environnement aléatoire
Rough talk notes (2002) [PDF]
Have you heard about the Mathematics Genealogy Project?
-
Chafaï, D. (supported
by Lyons, T. J.)
Computational Rough Paths (CoRoPa)
(2003)
Hosted by SourceForge.
Libraries of
C++ template
classes handling tree structures and free Lie algebras, including
Campbell-Baker-Hausdorff formula, shuffle product, Dynkin map, dynamic Hall
bases, etc. CoRoPa C++ is based on
the STL and is compatible with
GMP.
-
Chafaï, D.
The
pbsheet LaTeX2ε class (2006)
Simple
LaTeX2ε
document class for your problems sheets
-
Chafaï, D.
Introduction à qmail (1998)
Accessible documentation (in French) for
the MTA qmail.
Translated into Spanish by Prieto, J. Ivan Juanes (Greek and Latin teacher, Canary Islands, Spain)
- Read & write my name
- On my passports and ID
cards, my name is written Djalil Chafaï
- Djalil is my first name and
Chafaï is my surname (family name)
- English speaking people should read my name as Jalil Shaf-i-e
- French speaking people should read it as Djèlil Chaf-aille-i
- Arabic
speaking people may read it directly شاﻓﻌﻲ جلیل
- All the rest of the world may read
IPA
ʃaːfɪʕɪ dʒəlɪl
- Maybe I will try with
berber's
Tifinagh
or MP3 ;-)
- For (La)TeX you may write
Djalil Chafa\"{\i}
- For ArabTeX you may use
^sAfi`iy ^galiyl
- For HTML just write
Djalil Chafaï
- For xML you may use
arabic
or IPA
- Past
- Before joining Université Paris-Est, I have been working for various institutions including Université de Toulouse, Météo-France, University of Oxford, and INRA, as a teacher, engineer, and/or academic researcher.
-
Ould
Aoudia Salah Primary School (Annexe), Ben Aknoun, Algiers,
Algeria
[1978/9, 1981/2]
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Between Souk E'Tnin and Mechtrass, after Ighil Boul'Kadhi, W144 road, Maatkas district, Great Kabyle Region, Algeria
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Graphs
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Numbers
- Molecules
- ANR projects
- Videos
- Groups
- Affiliations
- People
- Opinion about the reform of French Universities (in French)
- Pour fonctionner, l'ascenseur social méritocratique a besoin à la fois d'élitisme et d'égalitarisme
- La réforme Pécresse s'attaque peu aux tares structurelles de l'enseignement supérieur français
- Beaucoup des capitaines d'industrie français sont issus des grandes écoles et ignorent tout de
la recherche
- Déplacer les prépas (avec leurs enseignants) des lycées vers les universités et les fondre dans un niveau L repensé
- Remplacer la sélection darwinienne au rabais du niveau L par une véritable sélection à l'entrée du niveau M
- Unifier le statut des universités et des grandes écoles, et mieux financer les universités
- Augmenter le nombre de supports IUF pour encourager les chercheurs de bon niveau
- Remplacer les emplois d'enseignants précaires (hors ATER) à l'université par des postes de PRAG
- Développer les systèmes de bourses et de prêts étudiants
- Remplacer la liberté d'inscription quelque soit le bac par des parcours à passerelles
- Mettre en place une évaluation des enseignements et des enseignants
- Rendre les conseils scientifiques et pédagogiques seuls maîtres du recrutement de leurs pairs
- Dans la même veine, la pétition Refonder l'université (mai 2009)
- If you think education is expensive, try ignorance Bok Derek
-
Papers
- Computer Science
- The Open Problems Project
- Assignment Problems, SIAM (2009) ISBN 978-0898716634
- Elements of information theory, Wiley (2006) ISBN 978-0471241959
- Randomized algorithms, Cambridge University Press, (1995) ISBN 978-0521474658
- Combinatorial optimization: packing and covering, SIAM (2001) ISBN 978-0898714814
- Probability theory and combinatorial optimization, SIAM (1997) ISBN 978-0898713800
- Combinatorial optimization: theory and algorithms, Springer (2008) ISBN 978-3540718437
- Combinatorial optimization: algorithms and complexity, Dover (1998) ISBN 978-0486402581
- An introduction to Kolmogorov complexity and its applications, Springer (1997) ISBN 978-0387948683
- Information theory, inference, and learning algorithms, Cambridge University Press (2003) ISBN 978-0521642989
- Elements of queueing theory: Palm-martingale calculus and stochastic recurrences, Springer (2003) ISBN 978-3540660880
- Discrete mathematics: elementary and beyond, Springer (2003) ISBN 978-0387955858
- Matching theory, AMS (2009) ISBN 978-0821847596
- Foundations and Trends® in Networking
- {0,1}∞
- It is amazing to realize how complex things in Mathematics and in Computer
Science can be reduced after all to 0 and 1, in other words, to the simple
notion of difference... Is it beautiful or disappointing? Well, maybe both!
Any resemblance to actual events is coincidental. In fact, and to be more
precise, we must say sequences of 0 and 1, making then more apparent the role of ∞. In a way, Computer Science is the reign of
finite sequences of 0 and 1 while Mathematics is the reign of infinite
sequences of 0 and 1, in other words, the reign of ∞. Between the two,
you may take a look at the concepts of
Turing machines
and Kolmogorov
complexity. You may also take a look
at Peano axioms
and Gödel's
incompleteness theorems. In Probability Theory, the modelling of the
Heads-or-Tails coin-tossing game involves a probability measure on
{0,1}∞, the set of infinite sequences of 0 and 1.
It has been shown recently that in a sense, almost all large statements are
indecidable, see for instance
- Probability & Statistics
- Open problems, by Yuval Peres
- Open problems, by David Aldous
- HomePage of François Baccelli
- Perfectly Random Sampling with Markov Chains, by David Bruce Wilson
- Imagine that in the year 2050, a Fields medal is awarded to a woman for her refoundation of statistics and its amazing implications in other sciences. Statistics is a subfield of mathematics which is not well considered by most mathematicians. A consequence is a general lack of statistical culture for the average mathematician, and also the massive presence of women in statistics (they avoid the competition with males by doing so). I encourage young mathematicians to open their mind, to learn the problems and concepts of statistics, and to teach statistics. By this way, they will find a job more easily, and they will improve the relationships between mathematics and the real world. There are no boundaries inside mathematics. The limits are in mathematicians minds, not in mathematics. So be curious! Impressive examples are given by
Persi Diaconis and
Terence Tao.
- Arthur Charpentier's blog (in French)
- Numerical Analysis
- Mathematics & Biology
- Mathematics & Physics
-
Le physicien traite les problèmes du véhicule à une roue (la brouette), à deux roues (tilbury ou bicyclette), à trois, à quatre roues. Le mathématicien traite le problème général du véhicule à n roues, n étant entier ou fractionnaire, positif ou négatif, réel ou imaginaire. Henri Bouasse
- Free software
- Minds
- Mathematicians
- The probabilistic quartet:
Andrey Nikolaevich,
Joseph Leo,
Paul Pierre, and
Kiyosi
-
Free probability: E. P. Wigner and J. von Neumann were schoolmates in Budapest and colleagues in Princeton.
-
András
Sárközy
and Carlo
Bruni never wrote a joint paper... (their
MR graph distance is 4)
- Roger-Dominique Bakry (1954 - )
-
Y'a qu'un nombre fini d'idées
-
À part Cauchy-Schwarz...
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Ce qui compte, en maths, c'est les idées
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En général, dans un papier, entre l'abstract et le non-sense, il y a l'introduction
-
De toute manière, tous les papiers sont faux, et ça n'est pas grave, car personne ne les lit
-
Tu ferais mieux de te trouver un vrai métier...
- Gian-Carlo Rota
(1932 - 1999)
- Ten Lessons I Wish I Had Been Taught, Notices of the AMS 44 (1997) [PDF]
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Don't fight with success
-
You should only listen to advice that you do not have to
follow
-
Daniel W. Stroock
(1940 - )
-
Mathematics is one, and possibly the only, human endeavor for which there is a widely, if not universally, recognized criterion with which to determine truth. For this reason, mathematicians can avoid some of the interminable disputes which plague other fields. On the other hand, I sometimes wonder whether the most interesting questions are not those for which such disputes are inevitable.
- Terence Chi-Shen Tao
陶哲軒 (1975 - )
- Timothy Gowers (1963 - )
- William P. Thurston (1946 - )
- Selected articles from Wikipedia
- Money
- Who said that mathematicians do not like money? It seems at least that the converse is
false...
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Papers
•
Students
•
Software
•
Miscellany
•
Enseignement (page dédiée)
