Lab seminars

Samer Dweik
Laboratoire de Mathématiques d’Orsay
Université Paris-Sud
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Thursday, December 15, 2016
14:00-15:00
KALMA conference room, 2nd floor

Abstract
After recalling some classical results about Monge’s transport problem and transport densities, we prove the summability of the transport density between two positives measures. The proof is based on a displacement interpolation argument and an approximation by a discrete measures. We prove also the summability of the transport density between a measure and its projection onto the boundary via symmetrization techniques.


Contact one of the Seminar’s organizers:
Badih Ghusayni (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Hassan Ibrahim (This email address is being protected from spambots. You need JavaScript enabled to view it.)

BEBBOUCHI Rachid
Président de la Société Mathématique d’Algérie
Laboratoire de Systèmes Dynamiques
USTHB, Alger, ALGERIE
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Wednesday, November 30, 2016
14:00-15:00
KALMA conference room, 2nd floor

Résumé
Dans le cadre du colloque HPM 2016 Mathématiques en Méditerranée qui se déroule du 18 au 22 Juillet 2016 à Montpellier, Evelyne Barbin et Léo Rogers animent un groupe sur l’enseignement actuel de la Géométrie et, pour avoir une base de données assez large, ils m’ont envoyé un questionnaire.
Dans cette contribution, je compte argumenter mes réponses aux questions posées, à savoir:
1.Qu’est devenu l’enseignement de la géométrie en Algérie depuis les années 1970?
2.Quelle est l’influence des institutions sur l’orientation de l’enseignement de la Géométrie en Algérie?
3.Qu’est-ce qui a changé dans la présentation de la Géométrie dans les livres scolaires et universitaires en Algérie?
4.Quel est le niveau en Géométrie des étudiants entrants à l’université algérienne?
En conclusion, l’enseignement de la Géométrie avant le baccalauréat est loin d’être satisfaisant. A l’Université quelques enseignements de base comme les courbes et surfaces ont été introduits pour les formations de mathématiciens mais le raisonnement géométrique n’est toujours pas suffisamment introduit.


Contact one of the Seminar’s organizers:
Badih Ghusayni (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Hassan Ibrahim (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Annie Raoult
Université Paris Descartes &
CNRS, Sorbonne Paris Cité, France

Tuesday, February 27, 2018
14:00-15:00
KALMA conference room, 2nd floor

ABSTRACT
Networks are ubiquitous in nature from mechanical trusses, atomistic lattices to biological tissues. It is natural to try and replace the discrete system that models their behavior by a continuous model that is expected to provide an equivalent or effective macroscopic behavior. In most cases, angular interactions are of primary mechanical or physical importance, but they make the mathematical analysis more difficult. An equivalent model for the myocardial tissue, for instance, has been derived by the so-called discrete homogenization method. The method applies as well to graphenes that recently received much industrial attention. Although a huge amount of mathematical literature has been devoted in the past few years to the variational continuum limit of discrete films, their intricate hexagonal geometry keeps graphenes outside of the range of applicability of most papers. We will present the specific analysis that has been performed in collaboration with Herv´e Le Dret. When bond interaction only is taken into account, the limit energy remains slightly reminiscent of the heuristic Cauchy-Born formula, but an homogenization procedure cannot be avoided. When angular interactions are present, we use a representation theorem. In both cases, the requested homogenization on an infinite number of cells makes the efficiency of the limit energy questionable.

Hussein Mortada
Université Paris 7
Institut de Mathématiques de Jussieu

Thursday, February 1, 2018
11:30-12:30
KALMA conference room, 2nd floor

ABSTRACT
We will show a link between the arc space (which is an algebro-geomtric object) and the identities of partitions of integer numbers: a partition of a positive integer number is simply a way of writing it as a sum of positive integer numbers. Integer partitions have a long and beautiful history in number theory. The link that we will describe, gives a new point of view on several known results and gives new theorems in this field.

Mariam Mourtada
American University of Beirut
Email : mariam This email address is being protected from spambots. You need JavaScript enabled to view it.

Thursday, December 1, 2016
14:00-15:00
KALMA conference room, 2nd floor

Abstract
Historically, L- functions have been studied in detail in many aspects, such as the distribution and location of their zeros, their special values, and so on. Recently, Y. Ihara has initiated a study of the distribution of values of logarithmic derivatives of L-functions, L’/L. Those differ from L-functions in being meromorphic functions rather than holomorphic functions. The logarithmic derivatives of L-functions, L’/L, are important in many applications. We will introduce the topic in its generality, and look at some new results in this field.


Contact one of the Seminar’s organizers:
Badih Ghusayni (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Hassan Ibrahim (This email address is being protected from spambots. You need JavaScript enabled to view it.)