Gia-Vuong Nguyen-Chu

Integrales orbitales unipotentes stables et leurs transformees de Satake

Memoires de la SMF 97 (2004), vi+110 pages

Resume :
Dans cet article, nous abordons quelques questions d'analyse harmonique sur les groupes reductifs p-adiques. Plus precisement, nous nous interessons a la transformation de Satake des distributions unipotentes stables dans le cas des groupes deployes. Ce probleme est motive, d'une part par les travaux de M. Assem sur le calcul des integrales orbitales unipotentes, et d'autre part par ceux de J.-L. Waldspurger sur la determination de l'espace des distributions unipotentes stables. Cette question est facile pour les groupes lineaires mais inconnue en general. Dans ce travail, nous traitons le cas des groupes . Pour n =2, nous demontrons que ces transformees de Satake s'expriment comme des fonctions regulieres sur le tore reel unitaire de dimension 2. Nous montrons ensuite que ces fonctions peuvent egalement etre retrouvees par la transformation de Satake des distributions de toute autre nature: les traces tordues compactes d'une famille explicite de representations de . Ce phenomene peut s'expliquer par l'endoscopie tordue entre et comme l'a remarque Arthur. Pour n >2, on demontre dans un certain nombre de cas que les transformees de Satake de telles traces sont effectivement des fonctions regulieres, d'une forme commune, sur le tore reel unitaire de rang n. On l'a en particulier verifie pour . On s'attend a ce que ceci reste vrai pour n quelconque. Grace a ces calculs, on propose alors une conjecture assez precise qui decrit les transformees de Satake des distributions unipotentes stables sur .

Mots clefs : Analyse harmonique, Groupes reductifs p-adiques, Algebres de Hecke, Transformation de Satake, Integrales orbitales unipotentes, Stabilite, Representations, Traces, Endoscopie tordue

Abstract:

Stable unipotent orbital integrals and their Satake transforms
In this article, we are concerned with some questions arising from harmonic analysis on p-adic groups. More precisely, we are interested in Satake transforms of stable unipotent distributions in the case of split groups. This problem is motivated, on one hand, by M. Assem's work on the computation of unipotent orbital integrals, and on the other hand, by J.-L. Waldspurgers' on the determination of the space of stable unipotent distributions. This question is easy for general linear groups but unkown in general. In this work, we deal with the groups . For n=2, we show that these Satake transforms are regular functions over the rank-2 unitary real torus. We then show that these functions can be recovered by the Satake transform of some distributions of a totally different kind: the twisted compact traces of an explicit familly of representations of . This phenomenon may be explained by twisted endoscopy between and as remarked by Arthur. For n > 2, we show, in some cases, that the Satake transforms of these traces are actually regular functions, of a common form, over the rank-n unitary real torus. In particular, we have verified it when . We expect that it is true in general. Thanks to these computations, we then propose a quite precise conjecture, that describes the Satake transforms of stable unipotent distributions on .

Key words: Harmonic analysis, p-adic reductive groups, Hecke algebras, Satake transform, Unipotent orbital Integrals, Stability, Representations, Traces, Twisted endoscopy

Pierre Berthelot - Jean-Marc Fontaine - Luc Illusie - Kazuya Kato - Michael Rapoport (Ed.)

Cohomologies p-adiques et applications arithmetiques (III)

Asterisque 295 (2004), xiv+300 pages

p-adic Hodge theory and values of zeta functions of modular forms
Kazuya Kato
Asterisque 295 (2004), 117-290

ISBN : 2-85629-157-0

Resume :
Theorie de Hodge p-adique et fonctions zeta de formes modulaires
Si f est une forme modulaire, nous construisons un systeme d'Euler attache a f, ce qui nous permet d'obtenir des bornes pour les groupes de Selmer de f. Une loi de reciprocite explicite permet de relier ce systeme d'Euler a la fonction zeta p-adique de f, ce qui nous permet d'obtenir un resultat de divisibilite en direction de la conjecture principale pour f ainsi que des minorations pour l'ordre d'annulation de cette fonction zeta p-adique. Dans le cas particulier ou f est attachee a une courbe elliptique E definie sur , nous prouvons que la fonction zeta p-adique de E a un zero en s=1 d'ordre superieur ou egal au rang du groupe des points rationnels de E.

Mots clefs : Forme modulaire, systeme d'Euler, groupe de Selmer, loi de reciprocite, fonction zeta p-adique, courbe elliptique

Abstract:

If f is a modular form, we construct an Euler system attached to f from which we deduce bounds for the Selmer groups of f. An explicit reciprocity law links this Euler system to the p-adic zeta function of f which allows us to prove a divisibility statement towards Iwasawa's main conjecture for f and to obtain lower bounds for the order of vanishing of this p-adic zeta function. In particular, if f is associated to an elliptic curve E defined over , we prove that the p-adic zeta function of f has a zero at s=1 of order at least the rank of the group of rational points on E.

Key words: Modular form, Euler system, Selmer group, reciprocity law, p-adic zeta function, elliptic curve

David Jerison, George Lustig, Barry Mazur, Tom Mrowka, Wilfried Schmid, Richard Stanley & S.-T. Yau

CDM 2003:
Current Developments in Mathematics 2003

ISBN: 1-57146-103-5

Binding: Hardcover
Page Number: 125
Year Published: 2004

These are the proceedings of the joint seminar by M.I.T. and Harvard on the current developments in mathematics for the year 2003. Established in 1995, this seminar has been continued on the third weekend of November every year. The organizing committee for the seminar consisted of distinguished mathematicians from the mathematics departments of both institutions: Barry Mazur, Wilfried Schmid, and S.T. Yau from Harvard, and David Jerison, Tom Mrowka, and Richard Stanley from M.I.T. This year, the seminar was dedicated to Prof. Wilfried Schmid and Prof. George Lusztig.

The 2003 speakers included Sergey Fomin, Henryk Iwaniec, Claire Voison, and Andrei Zelevinsky,

We would like to thank each of the contributors: without their participations, the seminar would not have been possible. We trust that these proceedings will be of interest to many mathematicians. And we hope that many of you will be able to join us for future seminars.

Contents

Cluster algebras: Notes for the CDM 2003 Conference - Sergei Fomin and Andrei Zelevinsky .1
AutomorphicNumber Theory - Henryk Iwaniec .35
On some problems of Kobayashi and Lang: Algebraic approaches - Claire Voison 83

The Math Forum

Dr. Math Introduces Geometry: Learning Geometry is Easy! Just ask Dr. Math!

ISBN: 0-471-22554-1
Paperback
192 pages
August 2004

Author Information

You, Too, Can Understand Geometry ? Just Ask Dr. Math !
Have you started studying geometry in math class? Do you get totally lost trying to find the perimeter of a rectangle or the circumference of a circle? Donft worry. Grasping the basics of geometry doesnft have to be as scary as it sounds. Dr. Math?the popular online math resource?is here to help!

Students just like you have been turning to Dr. Math for years asking questions about math problems, and the math doctors at The Math Forum have helped them find the answers with lots of clear explanations and helpful hints. Now, with Dr. Math Introduces Geometry, you'll learn just what it takes to succeed in this subject. Youfll find the answers to dozens of real questions from students who needed help understanding the basic concepts of geometry, from lines, rays, and angles to measuring three-dimensional objects and applying geometry in the real world. Pretty soon, everything from recognizing types of quadrilaterals to finding surface area to counting lines of symmetry will make sense. Plus, youfll get plenty of tips for working with tricky problems submitted by other kids who are just as confused as you are.

You won't find a better introduction to the world and language of geometry anywhere!

Hrishikesh (Rick) D Vinod, Derrick Reagle

Preparing for the Worst: Incorporating Downside Risk in Stock Market Investments

ISBN: 0-471-23442-7
Hardcover
286 pages
October 2004

Stock market investors have very different reactions to downside versus upside risk. This book begins by explaining the current treatment of stock market risk and methods of lowering that risk. The authors then show that many types of asymmetry of stock returns or investor reactions cause the existing theory to fail. They present the theory of downside risk and utility theory to account for the asymmetry, showing how the previous model can be adjusted for downside risk.


Eric Stade

Fourier Analysis

ISBN: 0-471-66984-9
Hardcover
442 pages
March 2005

Description

This pioneering resource tells the full story of Fourier analysis its history, its impact on the development of modern mathematical analysis, and today's applications. The topics are presented using a cause-and-effect approach, illustrating where ideas originated and what necessitated them. Rich in both theory and application, Fourier Analysis is an unique, thorough approach to this key topic in advanced calculus.

Table of Contents

Preface.
Introduction.
1. Fourier Coefficients and Fourier Series.
2. Fourier Series and Boundary Value Problems.
3. L2 Spaces: Optimal Contexts for Fourier Series.
4. Sturm-Liouville Problems.
5. A Splat and a Spike.
6. Fourier Transforms and Fourier Integrals.
7. Special Topics and Applications.
8. Local Frequency Analysis and Wavelets.
Appendix: Complex Numbers.
Exercises.
Exercises.
References.
Index.