Dr. Zelaci Hacen
University of El-Oued, Algeria
Email: zelaci-hacen@univ-eloued.dz

Website: https://sites.google.co/site/zhacen/

Sunday 14 november.

06:00-06:45 p.m
Title: Strange duality at level one for the anti-invariant vector bundles.

Abstract:

For a smooth algebraic curve of positive genus over the field of complex numbers, the strange duality says that the space of sections of certain theta bundle on moduli of bundles of rank r and level k is naturally dual to a similar space of sections of rank k and level r. In this talk, I will explain this duality and show that it remains true (at least at level one) on the moduli spaces of anti-invariant vector bundles.

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M'hammed Oudrane (PhD student) 
University of Côte d'Azur, France
Email: oudrane@unice.fr

Sunday 28 november
06:00-06:45 pm
Title: Regular projections and Lipschitz structures of real singular spaces.

Abstract:

The notion of regular projection is a strong tool in Lipschitz geometry of real singularities, it provides a way to prove metric properties of singular spaces by finding a finite number of directions which is transverse to the tangent space at the regular points of the singular set. We will be talking about how to prove the existence of regular projections for definable sets in polynomially bounded o-minimal structures ( ex: semi algebraic sets) and its application to the study of the Liptschitz structures and Lipschitz cell decomposition of definable sets in o-minimal structures.

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Dr. Sara Mehidi

University of Toulouse, France
Email: sara.mehidi@math.univ-toulouse.fr

Sunday 5th december.
06:00-06:45 p.m
Title: Extending torsors via log schemes.

Abstract:

We present here an approach to the problem of extension of torsors defined over the generic fiber of a family of curves. The question is to extend both the
structural group and the total space of the torsor above the entire family.
The origin of this subject is in the work of Grothendieck, who at the beginning of the years 1960, gave a good definition of the fundamental
group of algebraic varieties, based on the notion of étale Galois covers. The problem of extending torsors
under constant groups (and of orders prime to the characteristic of the residual field) has been solved,
on a general basis, by Grothendieck's fundamental group specialization theory.
When we are interested in algebraic varieties from an arithmetic point of view, it is natural to consider also torsors whose structural group is finite but not necessarily a constant group. We then talk of fppf torsors, with reference to the theory of faithfully flat descent. The point of view defended here is that in order to study the problem of extension of torsors, it is better to place ourselves in a larger frame where we allow the torsors to admit ramification : these are log flat torsors. So, we first search for a log extension for the intial torsor and then see if it comes from an fppf one.

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Souheib Allout (Phd Student)
Ruhr-University Bochum, Germany
Email: souheib.allout@rub.de

Sunday 12 december
06:00-06:45 pm
Title: Partially hyperbolic autonomous diffeomorphisms

Abstract:

The aim of this talk is to introduce the notions of hyperbolic, partially hyperbolic, autonomous,... diffeomorphisms. The style is to be more into giving examples and raising questions. Finally, we present an algebraic classification of autonomous diffeomorphisms in dimensions two and three.

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Dr. Adel Betina
Université de Vienne, Autriche
Website: https://sites.google.com/view/adelbetina/accueil

Email: adelbetina@gmail.com

Sunday 9 January
06:00-06:45 p.m
Title: On the failure of Gorensteinness at weight 1 Eisenstein points of the eigencurve.

Abstract:

Coleman and Mazur Introduced the p-adic eigencurve, a rigid analytic space parametrizing the system of Hecke eigenvalues of p-adic modular forms of finite slope.  I will present in this talk a joint work with Dimitrov and Pozzi in which we describe the geometry of the eigencurve at irregular weight one Eisenstein series. Such forms  belong to the intersection of the Eisenstein locus and the cuspidal locus of the eigencurve. We proved that the cuspidal locus is étale over the weight space at any irregular weight one Eisenstein series. As a corollary, we gave some applications in Iwasawa theory.

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Gaetan CANE  (Phd Student)
Université de Côte d'Azur, France
Website: https://math.unice.fr/~cane/
Email:  gaetan.cane@univ-cotedazur.fr

Sunday 16 january.
06:00-06:45 p.m
Title: Introduction à l'étude des modèles physiques par des outils stochastiques

Abstract:

Comprendre les comportements macroscopiques à partir des modèles microscopiques est un des objectifs de la physique statistique. Cependant, l'étude des modèles physiques non linéaires est extrêmement difficile, la chaîne anharmonique en est un parfait exemple. Un moyen de pouvoir étudier des modèles est de remplacer la non linéarité par un bruit stochastique. Dans cet exposé, je présenterai l'étude de la chaîne harmonique soumise à un bruit d'échange. Je montrerai comment à partir des équations microscopiques on peut observer le comportement macroscopique. L'exposé sera composé de deux parties ; la première partie sera composée des rappels de probabilités nécessaires pour comprendre la seconde. Dans celle-ci, j'étudierai la chaîne harmonique bruitée soumise à un champ magnétique. Je montrerai qu'à partir des équations de Newton on peut obtenir une équation de Boltzmann linéaire. Puis, au moyen d'un changement d'échelle temporelle et spatiale je montrerai comment on peut obtenir une équation de la chaleur fractionnaire dont l'exposant dépend de la présence ou non du champ magnétique introduit.

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Dr. Yacine Mokhtari
University of Bourgogne Franche-Comté, France
Website: https://sites.google.com/view/mokhtari-yacine/accueil

Email: yacine.mokhtari@univ-fcomte.fr

Sunday 23 january
06:00-06:45 p.m

Title: Boundary controllability of coupled wave equations in 1-D

Abstract:

In this talk, and after a brief introduction to control theory of PDEs, we present some results about boundary controllability of two coupled wave equations with first-order coupling in 1-D.

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Haroun Meghaichi (PhD Student)
Virginia tech, USA
Website:https://personal.math.vt.edu/haroun/index.html

Email: haroun@vt.edu

Sunday 30 january.
06:00-06:45 p.m
Title: An immersed discontinuous Galerkin method for elastic and acoustic-elastic wave propagation

Abstract:

We present an immersed discontinuous Galerkin method for solving acoustic-elastic interface problems.

The method allows elements to be cut by the interface and thus leading to elements consisting

of the union of an acoustic medium and an elastic medium. Thus, each interface element combines two separate models and is equipped with piecewise polynomial functions satisfying the interface jump conditions. The proposed discontinuous Galerkin formulation is stable and the IFE space contains optimally converging solutions. We present computational examples and results.

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Dr. Samir BEDROUNI
Université des Sciences et de la Technologie Houari Boumediene, Algérie
Website:http://perso.usthb.dz/~sbedrouni/

Email: bedrouni@usthb.dz

Sunday 13 february
06:00-06:45 p.m

Title: CONVEX FOLIATIONS OF DEGREE 4 ON THE COMPLEX PROJECTIVE PLANE

Abstract:

In this talk, I will present the main results of a recent paper in collaboration with D. Marín.
First, I will explain the outline of the proof of the result which states that up to automorphism of P^2_{C} there are 5 homogeneous convex foliations of degree four on P^{2}_{C}. Second, we will see how to use this result to obtain a partial answer to a question posed in 2013 by D. Marín and J. Pereira about the classification of reduced convex foliations on P^{2}_{C}.

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Cécile Gachet (PhD Student)
Université Côte d'Azur, France
Website: https://math.unice.fr/~gachet/

Email: haroun@vt.edu

Sunday 27 february.
06:00-06:45 p.m
Title: Abelian varieties with complex multiplication: some theory and an application

Abstract:

In this talk, I present a snapshot of the theory of abelian varieties with complex multiplication, or how the eigenvalues of possible automorphisms on an abelian variety may determine it up to isogeny or even up to isomorphism. I give a recent application of this theory: If A is an abelian variety and G is a finite group acting freely in codimension 2 such that the quotient A/G admits a resolution that is a Calabi-Yau variety, then A is isogenous to E^{dim A}, where E is one of two possible elliptic curves.

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