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X-WR-CALNAME:Département de mathématiques et applications
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X-WR-CALDESC:évènements pour Département de mathématiques et applications
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TZNAME:CEST
DTSTART:20180325T010000
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DTSTART:20181028T010000
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DTSTART:20190331T010000
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DTSTART:20191027T010000
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BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190312T160000
DTEND;TZID=Europe/Paris:20190312T173000
DTSTAMP:20260421T183449
CREATED:20190312T150000Z
LAST-MODIFIED:20211104T112241Z
UID:8503-1552406400-1552411800@www.math.ens.psl.eu
SUMMARY:Density of compressiblity in NIP theories
DESCRIPTION:Joint with Itay Kaplan and Pierre Simon.Distal theories are NIP theories which are ?Roewholly unstable?R. Chernikov and Simon’s ?Roestrong honest definitions?R characterise distal theories as those in which every type is compressible. Adapting recent work in machine learning of Chen\, Cheng\, and Tang on bounds on the ?Roerecursive teaching dimension?R of a finite concept class\, we find that compressibility is dense in NIP structures\, i.e. any formula can be completed to a compressible type in S(A). Considering compressibility as an isolation notion (which specialises to l-isolation in stable theories)\, we obtain consequences on the existence of models with certain properties.
URL:https://www.math.ens.psl.eu/evenement/density-of-compressiblity-in-nip-theories/
LOCATION:Sophie Germain salle 2015
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190312T140000
DTEND;TZID=Europe/Paris:20190312T170000
DTSTAMP:20260421T183449
CREATED:20190312T130000Z
LAST-MODIFIED:20211104T112225Z
UID:8498-1552399200-1552410000@www.math.ens.psl.eu
SUMMARY:Après-midi de théorie des groupes
DESCRIPTION:14.00-14.45  Emmanuel Militon (Nice)\, Groups of diffeomorphisms of a Cantor set15.00-15.45  Simon André (Rennes)\, Hyperbolicity is preserved under elementary equivalence15.45-16.15 coffee break(CANCELED) 16.15-17.00 Nikolay Nikolov (Oxford)\, On conjugacy classes in compact groups
URL:https://www.math.ens.psl.eu/evenement/apres-midi-de-theorie-des-groupes-4/
LOCATION:Salle W
CATEGORIES:Séminaire de théorie des groupes à l’ENS
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190312T140000
DTEND;TZID=Europe/Paris:20190312T153000
DTSTAMP:20260421T183449
CREATED:20190312T130000Z
LAST-MODIFIED:20211104T112226Z
UID:8500-1552399200-1552404600@www.math.ens.psl.eu
SUMMARY:Strongly NIP almost real closed fields
DESCRIPTION:The following conjecture is due to Shelah–Hasson: Any infinite strongly NIP field is either real closed\, algebraically closed\, or admits a non-trivial definable henselian valuation\, in the language of rings. We specialise this conjecture to ordered fields in the language of ordered rings\, which leads towards a systematic study of the class of strongly NIP almost real closed fields. As a result\, we obtain a complete characterisation of this class.
URL:https://www.math.ens.psl.eu/evenement/strongly-nip-almost-real-closed-fields/
LOCATION:Sophie Germain salle 1016
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190226T160000
DTEND;TZID=Europe/Paris:20190226T173000
DTSTAMP:20260421T183449
CREATED:20190226T150000Z
LAST-MODIFIED:20211104T112029Z
UID:8497-1551196800-1551202200@www.math.ens.psl.eu
SUMMARY:Uncountable categoricity of structures based on Banach spaces
DESCRIPTION:A continuous theory T of bounded metric structures is said to be kappa-categorical if T has a unique model of density kappa. Work of Ben Yaacov and Shelah+Usvyatsov shows that Morley’s Theorem holds in this context: if T has a countable signature and is kappa-categorical for some uncountable kappa\, then T is kappa-categorical for all uncountable kappa. In classical (discrete) model theory\, there are several characterizations of uncountable categoricity. For example\, there is a structure theorem for uncountably categorical theories T\, due to Baldwin+Lachlan: there is a strongly minimal set D defined over the prime model of T such that every uncountable model M of T is minimal and prime over D(M). Moreover (and easier)\, if T has such a strongly minimal set\, then T is uncountably categorical.In the more general metric structure setting\, nothing remotely like this is known. Indeed\, the metric analog of a strongly minimal set is nowhere to be seen\, at the moment. If one restricts attention to metric structures based on (unit balls) of Banach structures\, more is known. The appropriate analog of strongly minimal sets seems to be the unit balls of Hilbert spaces. After the speaker called attention to this phenomenon in some examples from functional analysis\, Shelah and Usvyatsov investigated it and proved a remarkable result (arxiv 1402.6513
URL:https://www.math.ens.psl.eu/evenement/uncountable-categoricity-of-structures-based-on-banach-spaces/
LOCATION:Sophie Germain salle 2015
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190219T160000
DTEND;TZID=Europe/Paris:20190219T173000
DTSTAMP:20260421T183449
CREATED:20190219T150000Z
LAST-MODIFIED:20211104T112028Z
UID:8496-1550592000-1550597400@www.math.ens.psl.eu
SUMMARY:On the theory of rigid meromorphic functions in positive characteristic
DESCRIPTION:There is a well-known analogy between the arithmetic of rational numbers and the theory of meromorphic functions over a normed field. It is a classical result of Julia Robinson that the first order theory of the field of rational numbers is undecidable\, and one would expect such a result in the meromorphic setting. In this talk I’ll give an outline of the proof of undecidability for rigid meromorphic functions in positive characteristic
URL:https://www.math.ens.psl.eu/evenement/on-the-theory-of-rigid-meromorphic-functions-in-positive-characteristic/
LOCATION:Salle 2015 Sophie Germain
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190215T160000
DTEND;TZID=Europe/Paris:20190215T173000
DTSTAMP:20260421T183449
CREATED:20190215T150000Z
LAST-MODIFIED:20211104T111801Z
UID:8490-1550246400-1550251800@www.math.ens.psl.eu
SUMMARY:Definable subsets of a Berkovich curve
DESCRIPTION:Let k be an algebraically closed complete rank 1 non-trivially valued field. Let X be an algebraic curve over k and let X^an be its analytification in the sense of Berkovich. We functorially associate to X^an a definable set X^S in a natural language. As a corollary\, we obtain an alternative proof of a result of Hrushovski-Loeser about the iso-definability of curves. Our association being explicit allows us to provide a concrete description of the definable subsets of X^S: they correspond to radial sets. This is a joint work with Jérôme Poineau.
URL:https://www.math.ens.psl.eu/evenement/definable-subsets-of-a-berkovich-curve/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190215T141500
DTEND;TZID=Europe/Paris:20190215T154500
DTSTAMP:20260421T183449
CREATED:20190215T131500Z
LAST-MODIFIED:20211104T111802Z
UID:8492-1550240100-1550245500@www.math.ens.psl.eu
SUMMARY:Tame topology and Hodge theory.
DESCRIPTION:I will explain how tame topology seems the natural setting for variational Hodge theory. As an instance I will sketch a new proof of the algebraicity of the components of the Hodge locus\, a celebrated result of Cattani-Deligne-Kaplan (joint work with Bakker and Tsimerman).
URL:https://www.math.ens.psl.eu/evenement/tame-topology-and-hodge-theory/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190215T110000
DTEND;TZID=Europe/Paris:20190215T123000
DTSTAMP:20260421T183449
CREATED:20190215T100000Z
LAST-MODIFIED:20211104T111802Z
UID:8491-1550228400-1550233800@www.math.ens.psl.eu
SUMMARY:Unlikely intersections with E x CM curves in A_2
DESCRIPTION:The Zilber-Pink conjecture predicts that an algebraic curve in A_2 has only finitely many intersections with the special curves\, unless it is contained in a proper special subvariety.Under a large Galois orbits hypothesis\, we prove the finiteness of the intersection with the special curves parametrising abelian surfaces isogenous to the product of two elliptic curves\, at least one of which has complex multiplication. Furthermore\, we show that this large Galois orbits hypothesis holds for curves satisfying a condition on their intersection with the boundary of the Baily–Borel compactification of A_2.More generally\, we show that a Hodge generic curve in an arbitrary Shimura variety has only finitely many intersection points with the generic points of a so-called Hecke–facteur family\, again under a large Galois orbits hypothesis.This is a joint work with Martin Orr (University of Warwick).
URL:https://www.math.ens.psl.eu/evenement/unlikely-intersections-with-e-x-cm-curves-in-a_2/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190212T140000
DTEND;TZID=Europe/Paris:20190212T170000
DTSTAMP:20260421T183449
CREATED:20190212T130000Z
LAST-MODIFIED:20211104T112225Z
UID:8499-1549980000-1549990800@www.math.ens.psl.eu
SUMMARY:Après-midi de théorie des groupes
DESCRIPTION:14.00-14.45 Joshua Frisch (Caltech) Proximal actions\, Strong amenability\, and Infinite conjugacy class groups15.00-15.45 Andy Zucker (Paris VII) Bernoulli Disjointness15.45-16.15 coffee break16.15-17.00 Christophe Garban (Université Lyon 1) Inverted orbits of exclusion processes\, diffuse-extensive-amenability and (non-?)amenability of the interval exchanges
URL:https://www.math.ens.psl.eu/evenement/apres-midi-de-theorie-des-groupes-5/
LOCATION:Salle W
CATEGORIES:Séminaire de théorie des groupes à l’ENS
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190205T160000
DTEND;TZID=Europe/Paris:20190205T173000
DTSTAMP:20260421T183449
CREATED:20190205T150000Z
LAST-MODIFIED:20211104T111801Z
UID:8489-1549382400-1549387800@www.math.ens.psl.eu
SUMMARY:Groupes d'automorphismes et Propriété (T)
DESCRIPTION:Nous présenterons une preuve de la Propriété (T) de Kazhdan pour les groupes d’automorphismes de structures métriques aleph_0-catégoriques. Ceci généralise des résultats précédents de Bekka (pour le groupe unitaire) et de Evans et Tsankov (pour les groupes pro-oligomorphes)\, sans besoin de faire appel à des résultats de classification de représentations unitaires. En effet\, l’argument est purement modèle-théorique et basé sur des principes de la stabilité locale.
URL:https://www.math.ens.psl.eu/evenement/groupes-dautomorphismes-et-propriete-t/
LOCATION:Sophie Germain salle 2015
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190129T160000
DTEND;TZID=Europe/Paris:20190129T173000
DTSTAMP:20260421T183449
CREATED:20190129T150000Z
LAST-MODIFIED:20211104T111800Z
UID:8488-1548777600-1548783000@www.math.ens.psl.eu
SUMMARY:Spectrum of the profinite completion of the integers
DESCRIPTION:Using ultraproducts\, I will describe the spectrum of the profinite completion of the integers and of the finite adeles over the rationals.The final aim is to describe the structure sheaf of these structures.Joint work with Margarita Otero and Angus Macintyre.
URL:https://www.math.ens.psl.eu/evenement/spectrum-of-the-profinite-completion-of-the-integers/
LOCATION:Sophie Germain salle 1016
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190122T140000
DTEND;TZID=Europe/Paris:20190122T170000
DTSTAMP:20260421T183449
CREATED:20190122T130000Z
LAST-MODIFIED:20211104T111601Z
UID:8486-1548165600-1548176400@www.math.ens.psl.eu
SUMMARY:Après-midi de théorie des groupes
DESCRIPTION:Tuesday\, 22 January14.00-14.45 Bertrand Rémy (Ecole Polytechnique)15.00-15.45 Tom Hutchcroft (Cambridge)15.45-16.15 coffee break16.15-17.00 Pavel Zalesski (University of Brasilia)Bertrand Remy\, Quasi-isometric invariance of continuous group Lp-cohomology\, and first applications to vanishings (joint with Marc Bourdon)We show that the continuous L^p-cohomology of locally compact second countable groups is a quasi-isometric invariant. As an application\, we prove partial results supporting a positive answer to a question asked by M. Gromov\, suggesting a classical behaviour of continuous L^p-cohomology of simple real Lie groups. In addition to quasi-isometric invariance\, the ingredients are a spectral sequence argument and Pansu?RTMs vanishing results for real hyperbolic spaces. In the best adapted cases of simple Lie groups\, we obtain nearly half of the relevant vanishings. Tom Hutchcroft\, Kazhdan groups have cost 1I will sketch a proof that Kazhdan groups have cost 1\, answering a question of Gaboriau. No knowledge of Kazhdan groups or of cost will be assumed. Joint work with Gabor Pete.Pavel Zalesski\, The profinite completion of 3-manifold groups.Abstract. We shall present structural results of the profinite completion widehat G of a 3-manifold group G and its interrelation with the structure of G. We shall address the question to what extent the profinite completion of the fundamental group $pi_1M of a 3-manifold determines the manifold M and discuss residual properties of pi_1 M.
URL:https://www.math.ens.psl.eu/evenement/apres-midi-de-theorie-des-groupes-3/
LOCATION:Salle W ENS
CATEGORIES:Séminaire de théorie des groupes à l’ENS
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190115T160000
DTEND;TZID=Europe/Paris:20190115T173000
DTSTAMP:20260421T183449
CREATED:20190115T150000Z
LAST-MODIFIED:20211104T111400Z
UID:8481-1547568000-1547573400@www.math.ens.psl.eu
SUMMARY:Density of the union of Cartan subgroups of  o-minimal groups
DESCRIPTION:Let G be a group. A subgroup H of G is a Cartan subgroup  ofG if H is a maximal nilpotent subgroup of G\, and for every normal finiteindex subgroup X of H\, X has finite index in its normalizer in G. \nWe consider Cartan subgroups of  definably connect groups definable inan o-minimal structure. In [BJ0] we proved that\, in this context\,Cartan subgroups of G exist\, they are definable and they fall infinitely many conjugacy classes. \nIn this talk I will prove that the union of the Cartan subgroups isdense in the group\, which was the main question left open in [BBO].(Joint work with Elías Baro and Alessandro Berarducci.) \n [BJ0] E.Baro\, E. Jaligot and M.Otero. Cartan subgroups of groupsdefinable in o-minimal structures\, J. Inst. Math. Juissieu 13 no. 4(2014) 849 – 893.
URL:https://www.math.ens.psl.eu/evenement/density-of-the-union-of-cartan-subgroups-of-o-minimal-groups/
LOCATION:Sophie Germain salle 2015
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190111T160000
DTEND;TZID=Europe/Paris:20190111T173000
DTSTAMP:20260421T183449
CREATED:20190111T150000Z
LAST-MODIFIED:20211104T111600Z
UID:8484-1547222400-1547227800@www.math.ens.psl.eu
SUMMARY:Tame open core and small groups in pairs of topological geometric structures
DESCRIPTION:Using the group configuration theorem\, Hrushovski and Pillay showed that the law of a group definable in the reals or the p-adics is locally an algebraic group law\, up to definable isomorphism. There are some natural expansions of these two theories of fields\, by adding a predicate for a dense substructure\, for example the algebraic reals or the algebraic p-adics. We will present an overview on some of the features of these expansions\, and particularly on the characterisation of open definable sets as well as of groups definable in the pairs.
URL:https://www.math.ens.psl.eu/evenement/tame-open-core-and-small-groups-in-pairs-of-topological-geometric-structures/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190111T141500
DTEND;TZID=Europe/Paris:20190111T154500
DTSTAMP:20260421T183449
CREATED:20190111T131500Z
LAST-MODIFIED:20211104T111400Z
UID:8482-1547216100-1547221500@www.math.ens.psl.eu
SUMMARY:Definability in the infinitesimal subgroup of a simple compact Lie group
DESCRIPTION:Joint work with Kobi Peterzil.Let G be a simple compact Lie group\, for example G=SO_3(R). We consider the structure of definable sets in the subgroup G^{00} of infinitesimal elements. In an aleph_0-saturated elementary extension of the real field\, G^{00} is the inverse image of the identity under the standard part map\, so is definable in the corresponding valued field. We show that the pure group structure on G^{00} recovers the valued field\, making this a bi-interpretation. Hence the definable sets in the group are as rich as possible.
URL:https://www.math.ens.psl.eu/evenement/definability-in-the-infinitesimal-subgroup-of-a-simple-compact-lie-group/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190111T110000
DTEND;TZID=Europe/Paris:20190111T123000
DTSTAMP:20260421T183449
CREATED:20190111T100000Z
LAST-MODIFIED:20211104T111559Z
UID:8483-1547204400-1547209800@www.math.ens.psl.eu
SUMMARY:Scrollar invariants\, resolvents\, and syzygies
DESCRIPTION:With every cover C -> P^1 of the projective line one can associate its so-called scrollar invariants (also called Maroni invariants) which describe how the push-forward of the structure sheaf of C splits over P^1. They can be viewed as geometric counterparts of the successive minima of the lattice associated with the ring of integers of a number field. In this talk we consider the following problem: how do the scrollar invariants of the Galois closure C’ -> P^1 and of its various subcovers (the so-called resolvents of C -> P^1) relate to known invariants of the given cover? This concerns ongoing work with Yongqiang Zhao\, in which we put a previous observation for covers of degree 4 due to Casnati in a more general framework. As we will see the answer involves invariants related to syzygies that were introduced by Schreyer. As time permits\, we will discuss a number-theoretic manifestation of the phenomena observed.
URL:https://www.math.ens.psl.eu/evenement/scrollar-invariants-resolvents-and-syzygies/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20190110T160000
DTEND;TZID=Europe/Paris:20190110T173000
DTSTAMP:20260421T183449
CREATED:20190110T150000Z
LAST-MODIFIED:20211104T112500Z
UID:14063-1547136000-1547141400@www.math.ens.psl.eu
SUMMARY:Sous-groupes qui pavent génériquement et géométrie des involutions
DESCRIPTION:(En collaboration avec Joshua Wiscons)L’exposé mélange théorie des modèles\, théorie des groupes\, et algèbre géométrique. On y parlera de groupes de rang de Morley fini\, mais il suffit de savoir naïvement ce qu’est une dimension à valeurs entières\, sans devoir maîtriser les finesses de la conjecture de Cherlin-Zilber.Un groupe abstrait porte peu d’information de nature géométrique\, même au sens des géométries d’incidence\, et c’est toujours remarquable si cela se produit.Le pur groupe SO(3\,R)\, par exemple\, permet de redéfinir l’espace projectif réel. PGL(2\,C) permet presque la même chose : il définit un fragment générique de l’espace projectif complexe. En fait cette situation est naturellement liée à la distribution des involutions et aux intersections entre conjugués de leur centralisateur\, qui pavent génériquement le groupe ambiant (tout cela sera expliqué dans SO(3\,R) et PGL(2\,C)).En suivant cette piste on peut obtenir des énoncés étonnamment forts\, généralisant au passage divers classiques sur les mauvais groupes ou sur les groupes définissablement linéaires de rang de Morley fini. On conjecture également que cette géométrie des involutions annonce un nouveau théorème d’identification pour PGL(2\, K).
URL:https://www.math.ens.psl.eu/evenement/sous-groupes-qui-pavent-generiquement-et-geometrie-des-involutions-2/
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181218T160000
DTEND;TZID=Europe/Paris:20181218T173000
DTSTAMP:20260421T183449
CREATED:20181218T150000Z
LAST-MODIFIED:20211104T111158Z
UID:8475-1545148800-1545154200@www.math.ens.psl.eu
SUMMARY:Les groupes virtuellement libres sont presque homogènes
DESCRIPTION:Perin et Sklinos\, et indépendamment Ould Houcine\, ont démontré en 2011 que les groupes libres sont homogènes : deux éléments qui ont le même type sont dans la même orbite sous l’action du groupe d’automorphismes. Dans cet exposé\, j’expliquerai que ce résultat reste presque vrai pour les groupes virtuellement libres\, au sens suivant : l’ensemble des éléments ayant le même type qu’un élément donné contient un nombre fini d’orbites sous le groupe d’automorphismes\, et ce nombre ne dépend pas de l’élément considéré. J’expliquerai également pourquoi je pense que ce résultat est optimal\, en donnant un exemple de groupe virtuellement libre dont je conjecture qu’il n’est pas homogène (travail en cours).
URL:https://www.math.ens.psl.eu/evenement/les-groupes-virtuellement-libres-sont-presque-homogenes/
LOCATION:Sophie Germain salle 2015
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181214T160000
DTEND;TZID=Europe/Paris:20181214T173000
DTSTAMP:20260421T183449
CREATED:20181214T150000Z
LAST-MODIFIED:20211104T111159Z
UID:8477-1544803200-1544808600@www.math.ens.psl.eu
SUMMARY:On differentially large fields.
DESCRIPTION:Recall that a field K is large if it is existentially closed in K((t)). Examples of such fields are the complex\, the real\, and the p-adic numbers. This class of fields has been exploited significantly by F. Pop and others in inverse Galois-theoretic problems. In recent work with M. Tressl we introduced and explored a differential analogue of largeness\, that we conveniently call « differentially large ». I will present some properties of such fields\, and use a twisted version of the Taylor morphism to characterise them using formal Laurent series and to even construct « natural » examples (which ultimately yield examples of DCFs and CODFs… acronyms that will be explained in the talk).
URL:https://www.math.ens.psl.eu/evenement/on-differentially-large-fields/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181214T110000
DTEND;TZID=Europe/Paris:20181214T123000
DTSTAMP:20260421T183449
CREATED:20181214T100000Z
LAST-MODIFIED:20211104T111358Z
UID:8478-1544785200-1544790600@www.math.ens.psl.eu
SUMMARY:Uniform bound for points of bounded degree in function fields of positive characteristic
DESCRIPTION:I will present a bound for the number of F_q[t]-points of bounded degree in a variety defined over Z[t]\, uniform in q. This generalizes work by Sedunova for fixed q. The proof involves model theory of valued fields with algebraic Skolem functions and uniform non-Archimedean Yomdin-Gromov parametrizations. This is joint work with Raf Cluckers and François Loeser.
URL:https://www.math.ens.psl.eu/evenement/uniform-bound-for-points-of-bounded-degree-in-function-fields-of-positive-characteristic/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181213T141500
DTEND;TZID=Europe/Paris:20181213T154500
DTSTAMP:20260421T183449
CREATED:20181213T131500Z
LAST-MODIFIED:20211104T111359Z
UID:8480-1544710500-1544715900@www.math.ens.psl.eu
SUMMARY:Ax-Lindemann-Weierstrass with derivatives and the genus 0 Fuchsian groups
DESCRIPTION:We prove the Ax-Lindemann-Weierstrass theorem for the uniformizing functions of genus zero Fuchsian groups of the first kind. Our proof relies on differential Galois theory of Schwarzian equations and machinery from the model theory of differentially closed fields. This result generalizes previous work of Pila-Tsimerman on the j function. (Joint work with James Freitag and Joel Nagloo)
URL:https://www.math.ens.psl.eu/evenement/ax-lindemann-weierstrass-with-derivatives-and-the-genus-0-fuchsian-groups/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181211T140000
DTEND;TZID=Europe/Paris:20181211T170000
DTSTAMP:20260421T183449
CREATED:20181211T130000Z
LAST-MODIFIED:20211104T111359Z
UID:8479-1544536800-1544547600@www.math.ens.psl.eu
SUMMARY:Après-midi de théorie de groupes
DESCRIPTION:14.00-14.45 Dawid Kielak (Bielefeld)Fibring of residually finite rationally-solvable groups14.45 -15.15 coffee break15.15-16.00 Damian Osajda (Wroclaw and McGill\, Montreal)A combination theorem for combinatorially non-positively curved complxes of hyperbolic groups
URL:https://www.math.ens.psl.eu/evenement/apres-midi-de-theorie-de-groupes-2/
LOCATION:Salle W
CATEGORIES:Séminaire de théorie des groupes à l’ENS
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181204T160000
DTEND;TZID=Europe/Paris:20181204T173000
DTSTAMP:20260421T183449
CREATED:20181204T150000Z
LAST-MODIFIED:20211104T111159Z
UID:8476-1543939200-1543944600@www.math.ens.psl.eu
SUMMARY:Sous-groupe additif générique d'un corps algébriquement clos de caractéristique positive.
DESCRIPTION:La théorie d’un corps algébriquement clos de caractéristique positive p muni d’un prédicat pour un sous-groupe additif admet une modèle-compagne ACF_pG. On se propose de décrire ce nouvel exemple de théorie NSOP_1\, en décrivant les imaginaires\, le Kim-forking et le forking. On parlera aussi de la généralisation de cette construction afin de présenter de nouveaux exemples de théories NSOP_1.
URL:https://www.math.ens.psl.eu/evenement/sous-groupe-additif-generique-dun-corps-algebriquement-clos-de-caracteristique-positive/
LOCATION:Sophie Germain salle 2015
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181120T160000
DTEND;TZID=Europe/Paris:20181120T173000
DTSTAMP:20260421T183449
CREATED:20181120T150000Z
LAST-MODIFIED:20211104T110958Z
UID:8470-1542729600-1542735000@www.math.ens.psl.eu
SUMMARY:Counting in pseudofinite structures
DESCRIPTION:In pseudofinite structures\, the non-standard size of definable sets often reveals important algebraic or model theoretic properties of the corresponding theories. In this talk\, we will give two new examples of this correlation. One is between the coarse dimension and the transformal transcendental degree in certain class of pseudofinite difference fields. The other example is that in pseudofinite H-strucures which are built from one-dimensional asymptotic classes\, the coarse dimension of a tuple corresponds to the coefficient of the leading term of SU-rank of this tuple. This is the first step to show that they are examples of multidimensional asymptotic classes (mac).
URL:https://www.math.ens.psl.eu/evenement/counting-in-pseudofinite-structures/
LOCATION:Salle 2015 Sophie Germain
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181116T160000
DTEND;TZID=Europe/Paris:20181116T173000
DTSTAMP:20260421T183449
CREATED:20181116T150000Z
LAST-MODIFIED:20211104T111157Z
UID:8473-1542384000-1542389400@www.math.ens.psl.eu
SUMMARY:Oscillatory integrals of subanalytic functions
DESCRIPTION:In several papers\, R. Cluckers and D. Miller have built and investigated a class of real functions which contains the subanalytic functions and which is closed under parameterized integration. This class does not allow any oscillatory behavior\, nor stability under Fourier transform. On the other hand\, the behavior of oscillatory integrals\, in connection with singularity theory\, has been heavily investigated for decades. In this talk\, we explain how to build a class of complex functions\, which contains the subanalytic functions and their complex exponentials\, and which is closed under parameterized integration and under Fourier transform.Our techniques involve appropriate preparation theorems for subanalytic functions\, and some elements of the theory of uniformly distributed families of maps.(joint work with R. Clucker\, G. Comte\, D. Miller and T. Servi).
URL:https://www.math.ens.psl.eu/evenement/oscillatory-integrals-of-subanalytic-functions/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181116T141500
DTEND;TZID=Europe/Paris:20181116T154500
DTSTAMP:20260421T183449
CREATED:20181116T131500Z
LAST-MODIFIED:20211104T110958Z
UID:8472-1542377700-1542383100@www.math.ens.psl.eu
SUMMARY:First-order logic in finitely generated fields
DESCRIPTION:The expressive power of first-order logic in the class of finitely generated fields\, as structures in the language of rings\, is relatively poorly understood. For instance\, Pop asked in 2002 whether elementarily equivalent finitely generated fields are necessarily isomorphic\, and this is still not known in the general case. On the other hand\, the related situation of finitely generated rings is much better understood by recent work of Aschenbrenner-Khélif-Naziazeno-Scanlon.Building on work of Pop and Poonen\, and using geometric results due to Kerz-Saito and Gabber\, I shall show that every infinite finitely generated field of characteristic not two admits a definable subring which is a finitely generated algebra over a global field. This implies that any such finitely generated field is biinterpretable with arithmetic\, and gives a positive answer to the question above in characteristic not two.
URL:https://www.math.ens.psl.eu/evenement/first-order-logic-in-finitely-generated-fields/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181116T110000
DTEND;TZID=Europe/Paris:20181116T123000
DTSTAMP:20260421T183449
CREATED:20181116T100000Z
LAST-MODIFIED:20211104T110958Z
UID:8471-1542366000-1542371400@www.math.ens.psl.eu
SUMMARY:Non-standard analysis and non-archimedean geometry
DESCRIPTION:In this talk I will describe a joint work (still in progress) with E. Hrushovski and F. Loeser\, in which we explain how the integrals I have defined with Chambert-Loir on Berkovich spaces can beseen (in the t-adic case) as limits of usual integrals on complex algebraic varieties
URL:https://www.math.ens.psl.eu/evenement/non-standard-analysis-and-non-archimedean-geometry/
LOCATION:ENS Salle W
CATEGORIES:Séminaire Géométrie et théorie des modèles
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181113T160000
DTEND;TZID=Europe/Paris:20181113T173000
DTSTAMP:20260421T183449
CREATED:20181113T150000Z
LAST-MODIFIED:20211104T110957Z
UID:8469-1542124800-1542130200@www.math.ens.psl.eu
SUMMARY:Groupes et anneaux oméga-catégoriques de fardeau fini
DESCRIPTION:Les groupes de fardeau fini sont les groupes NTP_2 qui correspondent aux groupes stables ou simples de rang fini. Or\, le fardeau est plus difficile à manipuler car il n’est pas forcément additif par fibration. Nous montrons que ces groupes sont virtuellement abélien-par-fini\, et les anneaux sont virtuellement fini-par-nuls. Ceci améliore un résultat de Kaplan\, Levi et Simon qui avaient démontré qu’un groupe dp-minimal est virtuellement nilpotent.Travail en commun avec Jan Dobrowolski
URL:https://www.math.ens.psl.eu/evenement/groupes-et-anneaux-omega-categoriques-de-fardeau-fini/
LOCATION:Salle 2015 Sophie Germain
CATEGORIES:Théorie des Modèles et Groupes
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181113T140000
DTEND;TZID=Europe/Paris:20181113T140000
DTSTAMP:20260421T183449
CREATED:20181113T130000Z
LAST-MODIFIED:20211104T111158Z
UID:8474-1542117600-1542117600@www.math.ens.psl.eu
SUMMARY:Après-midi de théorie de groupes
DESCRIPTION:Tuesday\, 13 November14.00-14.45 Miklos Abert (Renyi Institute Budapest)15.00-15.45 Arman Darbinyan (ENS Paris)15.45-15.15 coffee break16.15-17.00 Rachel Skipper (Göttingen and ENS Lyon)
URL:https://www.math.ens.psl.eu/evenement/apres-midi-de-theorie-de-groupes/
LOCATION:Salle W
CATEGORIES:Séminaire de théorie des groupes à l’ENS
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20181009T140000
DTEND;TZID=Europe/Paris:20181009T170000
DTSTAMP:20260421T183449
CREATED:20181009T120000Z
LAST-MODIFIED:20211119T102754Z
UID:8468-1539093600-1539104400@www.math.ens.psl.eu
SUMMARY:Après-midi de théorie des groupes
DESCRIPTION:14.00-14.45 Martin Bridson (Oxford)\, Profinite rigidity and hyperbolic 3-orbifolds15.00-15.45 Arnaud Hilion (Marseille): Boundary of cyclic hyperbolic extensions of free groups15.45-16.15 pause café16.15-17.00 Damien Gaboriau (ENS Lyon)\, On non-vanishing of the cohomology of Aut(Fn) and Out(Fn) in top dimensions
URL:https://www.math.ens.psl.eu/evenement/apres-midi-de-theorie-des-groupes-2/
LOCATION:ENS 45 rue    d’Ulm salle W  toits du DMA
CATEGORIES:Séminaire de théorie des groupes à l’ENS
END:VEVENT
END:VCALENDAR