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2011-2012    
ZHONG Changlong(University of Ottawa) 11h05 30/06/2012
Annihilators of torsion of Chow groups of homogeneous varieties 1 de 1
I will introduce some combinatorial constructions based on root system, and use it to provide an annihilator of torsion of gamma filtration of homogeneous varieties. Then I will mention a main application, which provides an annihilator of torsion part of the Chow group of a twist form. This is joint work with S. Baek and K. Zainoulline.
  SM-081
ZHONG Changlong(University of Ottawa) 10h00 30/06/2012
Comparison of Dualizing Complexes 1 de 1
In this talk I will introduce the dualizing complexes constructed by Moser, Spiess, Sato and Bloch (duality by Geisser), and talk about the comparison of these complexes.
  SM-080
GAO Ziyang(Paris 11) 10h00 23/06/2012
On the André-Oort conjecture for the product of modular curves 1 de 1
We give an unconditional proof of the André-Oort conjecture for arbitrary products of modular curves. Our approach uses the theory of o-minimal structures, a part of Model Theory. The strategy is proposed by J. Pila.
  SM-079
MA Li(Paris 6) 10h00 16/06/2012
p-adic Gross-Zagier formula 1 de 1
I will talk about Perrin-Riou's work on p-adic Gross-Zagier formula. The formula relates the p-adic height of a Heegner point on an elliptic curve with the first derivative of a p-adic L function associated to the curve.
  SM-078
JIANG Zhi(Pairs 11) 10h00 26/05/2012
An introduction to M-regular sheaves and GV-objects on abelian varieties 1 de 1
 
  SM-077
XIE Junyi(Ecole Polytechniques) 10h00 19/05/2012
Periodic points of birational maps of projective smooth surfaces 1 de 1
We introduce some basics on dynamics of surface birational maps. And we prove that if the first dynamical degree of a surface birational map is greater than one, then the periodic points are Zariski dense.
  SM-076
LU Huajun(CAS) 10h30 31/03/2012
Infinitesimal fiber of minimal regular models of elliptic curves 1 de 1
Let K be a discrete valuation field with ring of integers O_{K}. Let \pi be a uniformizing element of O_{K}. Let E be an elliptic curve over K. Let X be the minimal regular model of E over O_{K}. For any natural integer n, let X_{n}=X x Spec O_{K}/(\pi^{n+1}). I will present the following two topics:

1. The isomorphism class of X_{0} as a curve over the residue field k=O_{K}/(\pi). (finer than Kodiara-Neron classification)
2. The relation between X_{n} and X'_{n+m} where m>0 and X' is the minimal regular model of E over the ring O_{L} of integers of a finite galois extension L/K.
  SM-075
FU Lie(ENS) 10h00 24/03/2012
Autour des cycles algébriques 1 de 1
J'introduirai les conjectures concernant les cycles algébriques, notamment, la conjecture de Bloch-Beilinson, la conjecture de Murre, la conjecture de Hodge (usuelle ou généralisée ), les conjecture standards, la conjecture de Bloch (généralisée), la conjecture de nilpotence etc. J'expliquerai des résultats connus, et les relations entre ses conjectures. Si le temps permis, je vais expliquer en plus de détails sur les résultats de Kimura sur la conjecture de dimension finie de Kimura-O'Sullivan et ses applications.
  SM-074
TIAN Ye(CAS) 10h00 03/03/2012
Relative trace formula proof of Gross-Zagier theorem 1 de 1
Jacquet gave a relative trace formula proof of Waldspurger's formula. Based on his approach, we gave a relative trace formula proof of Gross-Zagier's theorem. This is joint work with Xinyi Yuan and Wei Zhang.
  SM-073
HU Yong(Paris 11) 10h00 25/02/2012
Serre's Conjecture II for classical groups 1 de 1
Let k be a perfect field of cohomological dimension 2. Serre's Conjecture II on Galois cohomology predicts that H^1(k, G)=1 for any semisimple simply connected algebraic group G over k. The goal of this talk is to introduce the machinery and sketch Bayer-Fluckiger and Parimala's proof of this conjecture for classical groups.
E. Bayer-Fluckiger and R. Parimala, Galois cohomology of the classical groups over fields of cohomological dimension <= 2, Invent. math. 122, 195-229 (1995) SM-072
LIANG Yongqi(Paris 11) 10h00 11/02/2012
Principe local-global pour les zéro-cycles: une synthèse 1 de 1
Je vous raconterai l'histoire de la conjecture de Colliot-Thélène et al. sur le principe local-global pour les zéro-cycles sur les variétés algébriques définies sur un corps de nombres.
  SM-071
SHEN Shu(Paris 11) 10h00 03/12/2011
Super connection, impaire classe de Chern et C^\infty RRG 1 de 1
Je vais présenter une analogue du theoreme de Riemann Roch Grothendieck pour l'image directe d'un fibre plat par une submersion.
http://math.berkeley.edu/~lott/jams.pdf SM-070
Jyoti Prakash SAHA(Paris 11) 10h00 12/11/2011
Control theorem for algebraic p-adic L-functions 1 de 1
Hida constructed a two-dimensional big Galois representation $T$ with coefficients in a certain Hecke algebra. This algebra has some special type of primes, called arithmetic primes which correspond to cusp forms. The representation $T$ when specialized at an arithmetic prime $P$ gives the usual two-dimensional representation $T(f_P)$ for the cusp form $f_P$ corresponding to $P$. We will prove a control theorem for the Selmer complex $R\Gamma_f(T)$ for $T$ at arithmetic primes, in the sense that, $R\Gamma_f(T) mod P = R\Gamma_f(T(f_P)$.
  SM-069
LEE Ting-Yu(Paris 6) 10h30 05/11/2011
Introduction to the arithmetic of classical groups 1 de 1
We focus on some basic facts about classical groups, and the relative classification about central simple algebra with involutions. Maybe not so arithmetic flavored.
  SM-068
JIANG Xun(Paris 11) 10h00 22/10/2011
Géométrie algébrique et géométrie analytique 1 de 1
Sur le douzième exposé de SGA 1 (le mémoire de M2 dirigé par M.Raynaud).
GAGA SM-067
 
 
   
2010-2011    
SHEN Shu(Paris 11) 10h00 25/06/2011
Autour du théorème de l'indice d'Atiyah-Singer II 1 de 1
C'est la deuxième partie de mon exposé sur le théorème de l'indice d'Atiyah-Singer. Il se consacre à montrer le théorème de Riemanne-Roch-Hirzebruch par la méthode du noyau de la chaleur. Cette partie est indépendante à la première partie de mon exposé.
  SM-066
SUN Zhe(Paris 11) 10h00 18/06/2011
Moduli spaces of convex projective structures on surfaces and Higher Teichmüller Spaces 1 de 1
 
arxiv1004.2894  arXiv:math/0405348  arXiv:math/0311149 SM-065
CHEN Miaofen(Paris 11) 14h15 13/06/2011
The determinant morphism for moduli spaces of p-disivible groups in the GL_n case.(suite) 2 de 2
 
  SM-064
CHEN Miaofen(Paris 11) 10h00 13/06/2011
The determinant morphism for moduli spaces of p-disivible groups in the GL_n case. 1 de 2
The moduli space of p-divisible groups is introduced by Rapoport and Zink and can be considered as local analogue of Shimura varieties. These spaces are representable by formal schemes. The objective of this talk is to study the geometrically connected components of the generic fiber of such Rapoport-Zink spaces with level structures. I will begin with the fundamental definitions and try to make this talk accessible to most of you.
  SM-063
David GRIMM(Universitaet Konstanz) 10h30 12/06/2011
Sums of squares in algebraic function fields 1 of 1
Not much is known about the relation of sums of squares in a function field and its field of constants. Suppose, for example, every sum of squares in the latter can be written as a sum of $n$ squares for some natural number $n$, is the same then true (with possibly a different $n$) for the entire function field? We address related questions in particular cases.
  SM-062
SUN Shenghao(Polytechnique) 14h15 04/06/2011
Hodge theory and intersection cohomology 2 of 2
 
  SM-061
SUN Shenghao(Polytechnique) 10h00 04/06/2011
Hodge theory and intersection cohomology 1 of 2
We start by reviewing the classical theory of Hodge and Lefschetz on the singular cohomology of complex algebraic manifolds. Then we present two approaches to generalize the theory to arbitrary algebraic varieties: Deligne's mixed Hodge structures and Goresky-MacPherson's intersection cohomology. In particular, we present the celebrated decomposition theorem of BBDG, and give many examples.
  SM-060
SHEN Shu(Paris 11) 10h00 07/05/2011
Autour du théorème de l'indice d'Atiyah–Singer I 1 de 1
C'est une série des exposes comme une introduction pour le théorème de l'indice d'Atiyah–Singer. En gros, le théorème dit que pour un opérateur elliptique, l'indice topologique égale l'indice analytique. Dans un premier temps, on commence par établir la théorie de Fredholm. Comme une application la périodicité de Bott sera montre.
  SM-059
Arno KRET(Paris 11) 10h00 30/04/2011
Lambda-adic representations associated to some simple Shimura varieties 1 of 1
We follow Kottwitz' construction of Galois representations associated to the automorphic representations which occur in the cohomology of certain compact Shimura varieties in cases where no endoscopy occurs. This is basically the content of Kottwitz paper in Inventiones with the same title as this talk. To prove that the construction is "correct" we will use another result of Kottwitz concerning the number of points of the Shimura varieties over finite fields. This number of points is expressed in a non-stable sum of orbital integrals of rational conjugacy classes in the reductive group. The proof of this formula and its stabilization could be subject of a future talk or talks.
  SM-058
SUN Shenghao(Polytechnique) 10h00 05/03/11
Sato-Tate for function fields 1 of 1
We explain Deligne's setting for the equidistributionproblem, and sketch the proof that "(1) implies (2)", namely the meromorphic continuation implies the non-vanishing. We then discuss the Sato-Tate conjecture for function fields, focusing on the case of elliptic curves.
Again I will try to make the talk accessible to a general audience.
  SM-057
SUN Shenghao(Polytechnique) 14h30 15/01/11
L-function method and equidistribution problem (Sato-Tate type of conjectures) 2 of 2
 
  SM-056
SUN Shenghao(Polytechnique) 10h00 15/01/11
L-function method and equidistribution problem (Sato-Tate type of conjectures) 1 of 2
abstract: The talk has two parts. In the first part, we explain in a general setting how to deduce the equidistribution of a sequence of conjugacy classes in a particular type of locally compact groups from the analytic properties of the L-functions attached to representations of these groups. In the second part, we will apply this general story to the special cases in which arithmetic geometers are interested, (hopefully) including both the number field case and the function 
field case. The approach we follow is due to Serre and Deligne.
Analysts are welcome too. SM-055
WU Han(École polytechnique fédérale de Lausanne) 10h00 12/12/2010
傅立叶分析与表示论(Fourier analysis and representation theory) 1 of 2
Abstract
horaire exceptionnel : dimanche     SM en partenariat avec un séminaire secret d'analyse .... SM-054
Javier FRESAN(Paris 13) 14h30 04/12/2010
Autour de la conjecture de Gross-Deligne 2 de 2
 
  SM-053
Javier FRESAN(Paris 13) 10h00 04/12/2010
Autour de la conjecture de Gross-Deligne 1 de 2
Cette série de deux exposés se donne pour but de présenter le travail de V. Maillot et D. Roessler autour de la conjecture de Gross-Deligne. Dans la première séance on énoncera cette conjecture reliant les périodes des variétés algébriques définies sur les corps de nombres algébriques aux valeurs spéciales de la fonction gamma. Ensuite, on montrera comment des outils profonds de la géométrie d'Arakelov, notamment le théorème de Riemann-Roch arithmétique équivariant, permettent de démontrer une version faible de la conjecture dans certains cas.
B. H. Gross, On the Periods of Abelian Integrals and a Formula of Chowla and Selberg, Invent. Math. 45 (1978), 193-211.          V. Maillot, D. Roessler, On the periods of motives with complex multiplication and a conjecture of Gross-Deligne, Ann. of Math. 160 (2004), 727-754.                                                                                                                                                        C. Soulé, Genres de Todd et valeurs aux entiers des dérivées de fonctions L, Séminaire Bourbaki 2005/2006, Exp. 955, Astérisque 311 (2007), 75-98. SM-052
SUN Shenghao(Polytechnique) 10h00 13/11/2010
On stacks 1 de ?
 
  SM-051
LU Chengyuan(Paris 13)                     Sauf si grève 10h00 06/11/2010
An introduction to a resolution to the modules of lie algebra 1 of 1
We will introduce some elementary theories of cohomology of Lie algebras and something around it.
  SM-050
LU Chengyuan(Paris 13) 14h30 30/10/2010
An introduction to a resolution to the modules of lie algebra 1 of 1
We will introduce some elementary theories of cohomology of Lie algebras and something around it.
  annulé
Ariyan JAVANPEYKAR(Paris 11-Leiden) 10h00 30/10/2010
The Grothendieck-Riemann-Roch theorem and heights for covers of surfaces with fixed branch locus 2 of 2
cf. 1 of 2
notes SM-049
Ariyan JAVANPEYKAR(Paris 11-Leiden) 10h00 23/10/2010
The Grothendieck-Riemann-Roch theorem and heights for covers of surfaces with fixed branch locus 1 of 2
The first part of this talk will consist of explaining the notions that go into the statement of the Grothendieck-Riemann-Roch theorem: Grothendieck's K_0-theory, intersection theory and characteristic classes. Some basic examples will be given. In my thesis I also give several applications. The main application being to the proof of a function field analogue of a conjecture by Edixhoven-de Jong-Schepers, the second part of this talk will consist mainly of discussing the latter.
notes SM-048
 
 
   
2009-2010    
Zhi JIANG(ENS) 10h10 17/04/2010
Pluricanonical systems on certain projective varieties  
Pluricanonical systems are the central objects in birational geometry. They are well understood on surfaces since Bomberi's work in 70's. But
only recently, breakthrough in higher dimensions is achieved by Hacon-McKernan, Takayama, Siu... I will report some recent progress.
  SM-047
Ting Yu LEE(Paris-6) 14h30 10/04/2010
Groupe de Travail sur Groupes Algébriques 1 of 2
 
  GdT-GA04
Cheng Yuan LU(Paris 13) 14h00 27/03/2010
An introduction to Moduli space of abelian varieties 1 of 1
We will understand the moduli space of abelian varieties with certain level sturcture by using the language of stacks. The course will contain an naive introduction of stacks.
  annulé
Wen Wei LI(Paris 7) 10h10 27/03/2010
Introduction à la théorie de Bruhat-Tits II 2 de 2
 
  SM-046
Wen Wei LI(Paris 7) 14h30 20/03/2010
Introduction à la théorie de Bruhat-Tits  
 L'immeuble de Bruhat-Tits est un certain complexe simplicial sur lequel un groupe réductif p-adique opère. Cette structure combinatoire encode des informations fines du groupe en question. On en esquissera laconstruction et des propriétés importantes ainsi que quelques applications, pour les groupes réductifs en général si possible. Les canons sont [BT1, BT2], tandis que [T] est souvent conseillé comme le meilleur guide; je suivrai parfois [L] dans l'exposé.
[BT1] F. Bruhat et J. Tits, Groupes réductifs sur un corps local I, Publ. Math. IHES, 41 (1972).
[BT2] F. Bruhat et J. Tits, Groupes réductifs sur un corps local II, Publ. Math. IHES, 60 (1984).
[T] J. Tits, Reductive Groups over Local Fields, in Proc. Symp. Pure Math. vol. 33 part 1 ("Corvallis" 1977).
[L] E. Landvogt, A Compactification of the Bruhat-Tits Building, Lecture Notes in Mathematics 1619, Springer-Verlag, 1996.
SM-045
Arno KRET(Paris 11) 10h10 20/03/2010
A Lefschetz trace formula for the cohomology of certain compact Shimura varieties 1 of 1
Let (G,X) be a PEL-type Shimura datum, and \rho a complex algebraic representation of G. To \rho is a complex vector bundle L  on the (analytical) Shimura tower. Let f be a function of the Hecke algebra of G(Q-hat) which is an elementary tensor of the form f = tensor_v f_v such that there exists a prime number v_0 such that f_v_0 is supported on the regular elements of G(Q_v_0). Then we have an "explicit" formula for the trace of f acting on the alternating sum cohomology of L.
The talk will consist of 3 parts, first we will introduce all the necessary notions in the above, then we give the trace, and in the last part we will give a detailed proof of this formula. The above theorem is a result of Fargues, proved in his thesis, Asterisque 291, chapter 6. Although we intend to define the things we are talking about, this talk will be somewhat technical and some background on Shimura varieties and cohomology is required.
  SM-044
Hao Ran WANG(Paris 6) 10h10 06/03/2010
$p$-adic unit ball and $p$-adic upper half plane  
Abstract: This talk is about elementary $p$-adic geometry. Two basic objects are concerned: unit balls and upper half plane. I will recall the basic notions in rigid analytic geometry. I will give an explanation of the upper half plane in this setting. You can think of these objects as examples of some definitions in my memoire.
  SM-043
Xu SHEN(Paris-11) 10h10 06/02/2010
On the Geometry and Cohomology of Some PEL-type Shimura Varieties-Talk 3. The cohomology of proper Shimura varieties 3 of 3
3)- interlude about deformation of finite flat group schemes (d'après Grothendieck-Illusie), formally lifting the above constructions to characteristic zero, Drinfeld level structures, interlude about formal vanishing cycles (d'après Berkovich), the isomorphism between pullbacks of vanishing cycles on Shimura varieties and on Rapoport-Zink spaces, the cohomology of Rapoport-Zink spaces, the cohomology of proper Shimura varieties.
  SM-042
Xu SHEN(Paris-11) 10h10 30/01/2010
On the Geometry and Cohomology of Some PEL-type Shimura Varieties-Talk 2. The geometry and cohomology of Newton polygon stratas 2 of 3
2)- solpe filtration of p-divisible groups, some distinguished central leaves, Igusa varities, a system of covering of the Newton stratas by Igusa varieties and truncated Rapoport-Zink spaces, the finiteness of the morphisms, application to cohomology. 
  SM-041
Xu SHEN(Paris-11) 10h10 23/01/2010
On the Geometry and Cohomology of Some PEL-type Shimura Varieties-Talk 1.  Basics about PEL-type Shimura varieties (unramified) 1 of 3
This series of talks will be mainly based on my M2 memoire of the works of Elena Mantovan, which generalizes Oort's almost product structure about the Newton polygon stratas of Siegel modular varieties, and Harris-Taylor's notion of Igusa varieties and their first basic identity for some special simple unitary Shimura varieties, to the PEL setting. It can also be viewed as a supplement and improvement of Rapoport-Zink's uniformization of PEL-type Shimura varieties.
 
There are some relevant and interesting topics, such as Chai's theory of canonical coordinates and p-adic monodromy of the central leaves, the work of Fargues on the cohomology of Rapoport-Zink spaces, the technique of counting points and stable trace formula method for Igusa varieties (initiated from Kottwitz, Langlands, etc, adapted to Igusa varieties by Harris-Taylor, and further developed by Shin). However, due to the time limitation, we will not touch these subjects.
1)- PEL-type Shimura varieties, basic examples, representability (via geometric invariant theory & Artin' criterion by local moduli respectively), complex period morphism and complex uniformization, local systems, Newton polygon stratification, Rapoport-Zink spaces, p-adic period morphism and p-adic uniformization.
le mémoire- demandez-le à l'auteur SM-040
Cheng Yuan LU(Paris-13) 14h30 16/01/2010
A Narrative of Serrre Conjecture 1 of 1
 
J.-P. Serre, Sur les représentations modulaires de degré 2 de Gal(\bar{Q}/Q) SM-039
Arno KRET(Paris-11) 10h30 16/01/2010
Le groupe fondamental des variétés abéliennes 1 de 1
On montrera que le groupe fondamental d'une variété abélienne est isomorphe au module de Tate complet(``full Tate module'')
  SM-038
Cheng Yuan LU(Paris-13) 19/12/2009 10h30
Simple modules of reductive groups 2,3 of 3
 
le mémoire SM-037
Yong Qi LIANG(Paris-11) 05/12/2009 10h30
Colliot-Thélène et la théorie de Galois inverse 1 de 1
Je voudrais expliquer pourquoi une conjecture de Colliot-Thélène implique une réponse affirmative du problème inverse de Galois sur Q (ou un corps de nombres quelconque).
[1]Topics in Galois theory par Serre. [2]An effective version of Hilbert's irreducibility theorem par Ekedahl SM-036
Cheng Yuan LU(Paris-13) 28/11/2009 14h30
Simple modules of reductive groups(mémoire de M2 dirigé par Tilouine) 1 of 3
 
le mémoire SM-035
Peng SHAN(Paris-7) 28/11/2009 10h30
La conjecture de Deligne-Langlands et algèbres de Hecke affine 1 de 1
 
  SM-034
Chun Hui WANG(Paris-11) 21/11/2009 14h30
Weil Representations 2 of 2
 
  SM-033
Chun Hui WANG(Paris-11) 21/11/2009 10h30
Weil Representations 1 of 2
 
  SM-032
Yong HU 14/11/2009 14h30
Groupe de Travail sur Groupes Algébriques  
cf. GdT-GA01
Groupes Algébriques-M.Demazure, P.Gabriel GdT-GA03
Marco MACULAN(Paris-11) 14/11/2009 10h30
Théorie géométrique des invariants et majorations de hauteurs 2 de 2
cf. 1 de 2
  SM-031
Marco MACULAN(Paris-11) 07/11/2009 10h30
Théorie géométrique des invariants et majorations de hauteurs(mémoire de M2 dirigé par Bost) 1 de 2
L'exposés se divisent en trois parties: les premières deux des rappels resp. sur la théorie géométrique des invariants (quand même les définitions,  les théorèmes principaux et des exemples) et sur les concepts fondamentaux de la géométrie d'Arakelov (fibrés hermitiens, et hauteurs "à la Arakelov" avec des exemples concrets). La troisième partie sera sur la minoration de hauteurs que présentée dans mon mémoire: après avoir les objets qui apparaissent, je voudrai donner la preuve dans un des deux cas (géométrique ou arithmétique) et, enfin, conclure en montrant comment ce résultat peut être utilisé en géométrie diophantienne.
le mémoire SM-030
Yong HU 31/10/2009 10h30
Groupe de Travail sur Groupes Algébriques  
cf. GdT-GA01
Groupes Algébriques-M.Demazure, P.Gabriel GdT-GA02
Arno KRET(Paris-11) 24/10/2009 10h00
Modular forms from a moduli perspective 3,4 of 4
3) Automorphic forms. Recall the definition of cuspidal autom forms on GL_2. Make the passage from modular forms (as explained in the previous chapter) to automorphic forms, and state PRECISELY what the relation is between the two. I will end with the conclusion that the theorem of modularity implies the global Langlands conjecture for the Galois representations which occur in the Tate module of an elliptic curve. (this chapter will take probably 2 talks)
cf. 1 of 4 SM-029
Yong HU 17/10/2009 10h00
Groupe de Travail sur Groupes Algébriques  
In the opening lectures of this GdT, I would like to give a quick but informative
introduction to the langue used in the book "Groupes Algebriques" (by Demazure and
Gabriel). The goal is to familiarize ourselves to the following notions/results: 
k-functors (with k a ring), functors between k-functors and locally ringed spaces,
construction of grassmannians, local functors, open subfunctors, characterization of
functors representable by schemes (comparison theorem), extension and (Weil)
restriction of scalars. 
Groupes Algébriques-M.Demazure, P.Gabriel           notes GdT-GA01
Arno KRET(Paris-11) 10/10/2009 14h00
Modular forms from a moduli perspective 2 of 4
2) Modular forms. Introduce modular forms as sections of the sheaf of relative differentials on the universal elliptic curve. Move towards functions of lattices, derive the classical formulas that define modular forms as holomorphic functions on the complex upper half plane satisfying certain transformation rules w.r.t. a certain congruence subgroup of SL_2(Z).
cf. 1 of 4    notes SM-028
Ting Yu LEE(Paris-6) 10/10/2009 10h00
Flasque resolutions of algebraic tori 1 of 1
sur le mémoire de M2 dirigé par P.Gille, pour le résumé cf. le lien suivant.
le mémoire SM-027
Arno KRET(Paris-11) 03/10/2009 10h00
Modular forms from a moduli perspective 1 of 4
Abstract: Classically modular forms are defined on the complex half plane as functions satisfying certain transformation properties. In this series of these talks I will define modular forms as certain sections of a certain line bundle on the universal elliptic curve representing a certain moduli problem. I will then move towards the classical formulas which define modular forms.
The aim of these talks is to provide a more conceptual understanding of what modular forms are, rather than just giving a bunch of formulas that define them.

1) Brief review of elliptic curves over arbitrary base (no proofs here, only statements and defs). (relatively) (representable) moduli problems, geometric properties of moduli problems, examples of moduli problems: the 4 basic moduli problems and their properties of representability. (Coarse moduli schemes, if time permits)

References: Talk notes of Edixhoven on GL_2 (part 3 is basically copied from his notes),
http://www.math.leidenuniv.nl/~edix/talks/2009_02_09/GL2.pdf and the original handwritten notes,
http://www.math.leidenuniv.nl/~edix/talks/2009_02_09/GL2_handwritten.pdf.
Deligne, in SPM 349.
The book Katz Mazur, the Arithmetic moduli of elliptic curves. Chapters 2 and 4.
Thesis of Johan Bosman, http://www.uni-due.de/~ada649b.
Talk notes of Edixhoven for the course topic in arithmetic geometry that he gave in Leiden sept '09,
http://www.math.leidenuniv.nl/~edix/tag_2009/tag1-2.html
SM-026
 
 
   
2008-2009    
Yih Dar SHIEH(Paris-11 ALGANT) 28/06/2009(dimanche) 10h00
  1 of 1
I will sketch Bombieri's proof of Riemann Hypothesis for algebraic curves, which used only Riemann-Roch theorem and basic Galois Theory. In the second part, I describe (two) applications of Artin-Schreier extension to exponential sum and coding theory. If possible, I will mention the relation of exponential sum and factors of Jacobians.
  SM-025
Wen Wei LI(Paris-7) 30/05/2009 10h00
Un aperçu de la formule des traces d'Arthur-Selberg 3 de ?
cf. 1 de ?
ref. J. Arthur, An Introduction to the Trace Formula   S. Gelbart, Lectures on the Athur-Selgerg Trace Formula SM-024
Wen Wei LI(Paris-7) 23/05/2009 10h00
Un aperçu de la formule des traces d'Arthur-Selberg 2 de ?
cf. 1 de ?
ref. J. Arthur, An Introduction to the Trace Formula   S. Gelbart, Lectures on the Athur-Selgerg Trace Formula SM-023
Wen Wei LI(Paris-7) 16/05/2009 10h00
Un aperçu de la formule des traces d'Arthur-Selberg 1 de ?
La formule des traces fut inventée par Selberg en 1956 pour traiter questions arithmétiques liées au groupe SL(2). Une généralisation à
groupes réductifs est obtenue par Arthur pendant 1974-2003. Elle permet de déduire, par exemple, la correspondance de
Jacquet-Langlands, changement de base cyclique (apparu dans la démonstration du théorème de modularité) et les résultats récents sur
la conjecture de Sato-Tate. Soyons réalistes, nous nous contenterons d'exposer les idées de base.
ref. J. Arthur, An Introduction to the Trace Formula   S. Gelbart, Lectures on the Athur-Selgerg Trace Formula SM-022
Yong Qi LIANG(Paris-11) 21/03/2009 14h15
Théorèmes de dualité en arithmétique (suite) 1 de 1
Je vais vous expliquer la dualité en arithmétique en terme de la cohomologie étale (de Artin-Verdier), et TDA pour les variétés algébriques sur un corps global, et finalement TDA pour les 1-motives.
  SM-021
Guo Dong ZHOU(Universität zu Köln - Allemagne) 21/03/2009 10h00
Sur une conjecture d'Auslander and Reiten 1 de 1
Une conjecture d'Auslander-Reiten dit que si les categories stables de deux algebres de dimension finie definies sur un corps algebriquement clos sont equivalentes, alors ces deux algebres ont meme nombre des classes d'isomorphismes des modules simples non-projectifs. Dans cet expose, on s'interesse a cette conjecture pour une equivalence stable de type de Morita qui a ete introduite par Broue dans les annees 90. On donnerai des conditions equivalentes de cette conjecture, Le point critique est de definir une notion de l'homologie de Hochschild stable de degre zero.
  SM-020
Yong Qi LIANG(Paris-11) 14/03/2009 10h00
Quelques théorèmes de dualité en arithmétique 1 de 1
Je vais parler de l'histoire de théorèmes de dualité en arithmétique. Les résultats principaux sur ce sujet seront énoncés. Mais il n'y aura peu de preuves dans cet exposé.
le mémoire SM-019
Arno KRET(Leiden University - The Netherlands) 21/02/2009 10h00
The global Langlands conjecture 2 of 2
cf 1 of 2
  SM-018
Arno KRET(Leiden University - The Netherlands) 14/02/2009 10h00
The global Langlands conjecture 1 of 2
In these two talks I will give a statement of the Langlands conjecture for the field Q.

Let l be a prime number and A the ring of Q-adeles. The Langlands conjecture sets up a bijection between (isomorphism classes of) automorphic representations of Gl_n(A) to geometric l-adic representations of the absolute Galois group of Q, such that L-factors correspond to L-factors.

The goal of my talk will be to explain all the words occurring in the above phrase (except prime number, number field and bijection maybe...). I try to be as easy and precise as possible, after all it is Saturday.
  SM-017
Alena PIRUTKA(Paris-11) 13/12/2008 10h00
Etude de la $R$-équivalence sur des variétés rationnellement connexes 3 de 3
cf. 1 de 3
le texte SM-016
Alena PIRUTKA(Paris-11) 06/12/2008 10h00
Etude de la $R$-équivalence sur des variétés rationnellement connexes 2 de 3
cf. 1 de 3
  SM-015
Xu SHEN(Paris-11 ALGANT M2) 29/11/2008 14h15
On Deligne-Lusztig theory and non-abelian Lubin-Tate theory 2 of 2
cf. 1 of 2
  SM-014
Alena PIRUTKA(Paris-11) 29/11/2008 10h00
Etude de la $R$-équivalence sur des variétés rationnellement connexes 1 de 3
résumé
  SM-013
Giovanni Di Matteo 22/11/2008 14h15
Les bornés de Serre pour GL_n(k) 2 of 4
cf. SM-003
  SM-012
Xu SHEN(Paris-11 ALGANT M2) 22/11/2008 10h00
On Deligne-Lusztig theory and non-abelian Lubin-Tate theory 1 of 2
In this talk, we shall first review the classical Deligne-Lusztig theory, which gives all the irreducible representions of the reductive groups over finite fields, by the l-adic cohomology with compact support of certain smooth algebraic varieties ( Deligne-Lusztig varieties ) over the algebraic closure of the finite field. Then we turn to the calculation of the vanishing cycle cohomology of the Lubin-Tate deformation space in the depth 0 case. Following Yoshida, we will construct some suitable models of this moduli space by some successive blowing-ups and normalization. We will at last reduce to the calculation of the cohomology of the Deligne-Lusztig variety contained as a special fibre in a model constructed above, and thus obtain a purely local proof of the result asserted by Harris-Taylor in this special case.
  SM-011
Ramla ABDELLATIF(Paris-11) 15/11/2008 10h00
Représentations modulo p de GL_2(F) III : Second construction de Paskunas - Perspectives 3 de 3
Résumé / Abstract
  SM-010
Ramla ABDELLATIF(Paris-11) 08/11/2008 10h00
Représentations modulo p de GL_2(F) II : Le cas de Q_p (2-ième partie) - Première construction de Paskunas 2 de 3
Résumé / Abstract
  SM-009
Yong HU(Paris-11) 25/10/2008 14h15
R-equivalence and 0-cycles on 3-dim. tori II : K-theory of toric models and the proof of Merkerjev's
theorem
2 of 2
cf. SM-005
Main references:
[1] J.-L. Colliot-Thelene, J.-J. Sansuc, "La R-equivalence sur les tores", Ann. Sci. Ecole Norm. Sup. (4) 10 (1977), 175&#53;&#8211;229.

[2] W. Fulton, "Intersection theory", 2nd ed., Springer&#114;&#8211;Verlag, 1998.

[3] A. Merkurjev, "R-equivalence on 3-dimensional tori and zero-cycles", Algebra and Number Theory, to appear, http://www.math.ucla.edu/~merkurev/publicat.htm

[4] D. Quillen, "Higher algebraic K -theory I", in LNM. 341, Algebraic K -theory I, Springer-Verlag (1973), 85&#53;&#8211;147.
SM-008
Ramla ABDELLATIF(Paris-11) 25/10/2008 10h00
Représentations modulo p de GL_2(F) I : Présentation générale - le cas de Q_p (1-ière partie) 1 de 3
Résumé / Abstract
le mémoire SM-007
Wen-Wei LI(Paris-7) 18/10/2008 14h15
La représentation de Weil et son caractère 3 de 3
On introduira des notions fondamentales du groupe metapléctique et représentation de Weil. On en parlera aussi l'analyse harmonique et des applications arithmétiques.
le mémoire SM-006
Yong HU(Paris-11) 18/10/2008 10h00
R-equivalence and 0-cycles on 3-dim. tori I : Chow groups with the link to K-theory, and R-equivalence on tori 1 of 2
This seris of talks, based on my master thesis done at Leiden,aims to explain the following theorem recently proved by A.Merkerjev:

Theorem: Let T be an algebraic torus over a field k,and let X be a smooth compactification of T. Suppose dim T\le 3. Then the map:
\phi: T(k)/R \rightarrow A_0(X);  t\mapsto [t]-[1]    is an isomorphism of groups, where T(k)/R is the group of R-equivalence classes on the rational points of T and A_0(X) is the group of 0-cycle classes of degree 0 on X.

Although the result obtained is not of too much generality, this theorem is beautiful in my view, because it has made connections
between many interesting arithmetic or algebro-geometric objects. To these objects, I'll try to give a brief introduction with an effort
to minimize the set of abstract definitions in need. After that, the talk will be focused on ideas about how the knowledge of these objects helps to prove the main theorem.
 
le mémoire SM-005
Wen-Wei LI(Paris-7) 11/10/2008 14h00
La représentation de Weil et son caractère 2 de 3
On introduira des notions fondamentales du groupe metapléctique et représentation de Weil. On en parlera aussi l'analyse harmonique et des applications arithmétiques.
le mémoire SM-004
Giovanni Di Matteo 11/10/2008 10h00
The algebraic fundamental group, Cebotarev's density theorem, and the foundations of étale cohomology 1 of 4
Abstract
  SM-003
Chun Hui WANG(Paris-11) 04/10/2008 14h30
Rationality of the zeta function of algebraic variety 1 of 1
For higher dimensional varieties,the rationality of the zeta function and the functional equation were first proved by Dwork in 1960,using the methods of p-adic analysis.It is an important event in the struggling process for the Weil conjecture. On this petite report, I will try to recover the mostly part of the proof.
  SM-002
Wen-Wei LI(Paris-7) 04/10/2008 10h00
La représentation de Weil et son caractère 1 de 3
On introduira des notions fondamentales du groupe metapléctique et représentation de Weil. On en parlera aussi l'analyse harmonique et des applications arithmétiques.
le mémoire SM-001