Workshop: In Honour of the 60th Birthday of Irene Fonseca

05/16/2016 - 00:00
05/20/2016 - 23:59
Location: 
Université de Montréal Pavillon André-Aisenstadt 2920, Chemin de la tour, 5th floor Montréal (Québec) H3T 1J4 CANADA .
Abstract: 

 

Workshop: New Challenges for the Calculus of Variations Stemming From Problems in the Materials Sciences and Image Processing - In Honour of the 60th Birthday of Irene Fonseca

Organizers :
Rustum Choksi (McGill University)
Nicola Fusco (Università degli Studi di Napoli “Federico II”)
Christopher J. Larsen (Worcester Polytechnic Institute)
Giovanni Leoni (Carnegie Mellon University)

 

Web site : http://www.crm.umontreal.ca/2016/Fonseca16/index_e.php

Last edited by on Thu, 05/12/2016 - 15:18

On ratios of harmonic functions

05/13/2016 - 13:30
05/13/2016 - 14:30
Speaker: 
Eugenia Malinnikova, Trondheim/Purdue
Location: 
Seminar Montreal Analysis Seminar McGill, Burnside Hall, 805 Sherbrooke Str West, Room 920
Abstract: 

 We consider pairs of harmonic functions in the unit ball of R^n with the same zero set Z and prove that the ratio is a well-defined real-analytic function that satisfies the maximum principle, the Harnack inequality and a certain gradient estimate. Some examples of such pairs will be discussed. We will show that he constants in these inequalities depend only on the zero set Z, moreover, in dimension two the dependence is only on the length of the zero set. This is a joint work with A. Logunov.

Last edited by on Mon, 05/09/2016 - 15:49

L'équation aux différences avant de Newton pour les fonctions de mots

05/13/2016 - 13:30
05/13/2016 - 14:30
Speaker: 
Jean-Éric Pin, LIAFA, Université Paris Diderot
Location: 
Seminar LACIM 201, av. du Président-Kennedy, LOCAL PK-4323, Montréal (Qc) H2X 3Y7
Abstract: 

 L'équation aux différences avant de Newton donne une expression d'une fonction de $N$ dans $Z$ en termes de la valeur initiale de la fonction et des puissances de l'opérateur de difference avant. Une extension de cette formule aux fonctions de $A*$ dans $Z$ a été donnée en 2008 par P. Silva et le présentateur. Dans cet article, cette formule est à nouveau généralisée, cette fois aux fonctions de $A*$ dans le groupe libre sur $B$.

Last edited by on Mon, 05/09/2016 - 15:47

Scalable Software Testing and Verification Through Heuristic Search and Optimization: Experiences and Lessons Learned

05/13/2016 - 10:00
05/13/2016 - 11:00
Speaker: 
Lionel Briand, University of Luxembourg
Location: 
Colloquium DIRO Université de Montréal, Pavillon Claire-McNicoll, salle Z-317
Abstract: 

 Testing and verification problems in the software industry come in many different forms, due to significant differences across domains and contexts. But one common challenge is scalability, the capacity to test and verify increasingly large, complex systems. Another concern relates to practicality. Can the inputs required by a given technique be realistically provided by engineers?

This talk reports on 10 years of research tackling verification and testing as a search and optimization problem, often but not always relying on abstractions and models of the system under test. Our observation is that most of the problems we faced could be re-expressed so as to make use of appropriate search and optimization techniques to automate a specific testing or verification strategy.

Last edited by on Mon, 05/09/2016 - 15:45

XIXe colloque panquébécois des étudiants de l’Institut des Sciences Mathématiques (ISM)

05/13/2016 - 00:00
05/15/2016 - 23:59
Location: 
UQAM
Abstract: 

 

Organizers :
Fils Geasino Fotso (UQÀM)
Kasia Jankiewicz (McGill University)
Nadia Lafrenière (UQÀM)
Mélodie Lapointe (Université du Québec à Montréal)

Web site : http://www.lacim.uqam.ca/~ism2016/index.html

Last edited by on Mon, 05/09/2016 - 15:44

Workshop: Applications and New Frontiers for the Finite Element Method

05/09/2016 - 00:00
05/13/2016 - 23:59
Location: 
Université Laval GIREF
Abstract: 

 Organizers :
José Manuel Urquiza (Université Laval)
Jean Deteix (Université Laval)
Miguel Ángel Fernández (Inria Paris-Rocquencourt)
André Fortin (Université Laval)
André Garon (École Polytechnique de Montréal)

http://www.crm.umontreal.ca/2016/Element16/index_e.php

 

 

Last edited by on Mon, 05/09/2016 - 15:43

On small gaps in the length spectrum

05/09/2016 - 15:30
Speaker: 
Dmitry Jakobson, McGill University
Location: 
McGill, Burnside Hall, 805 Sherbrooke Str West, Room 920
Abstract: 

 This is joint work with Dmitry Dolgopyat.  We discuss upper and lower bounds for the size of gaps in the length spectrum of negatively curved manifolds. For manifolds with algebraic generators for the fundamental group, we establish the existence of exponential lower bounds for the gaps.
On the other hand, we show that the existence of arbitrary small gaps is topologically generic: this is established both for
surfaces of constant negative curvature, and for the space of negatively curved metrics. While arbitrary small gaps are topologically generic, it is plausible that the gaps are not too small for almost every metric.  We present a result in that direction.  

Last edited by on Mon, 05/09/2016 - 15:41

Why conservation biology needs mathematics

05/06/2016 - 19:30
05/06/2016 - 20:30
Speaker: 
Stephanie Peacock, University of Alberta, University of Toronto
Location: 
Université de Montréal, Pavillon Jean-Coutu, 2940, chemin de Polytechnique, salle S1-111 (salle Apotex)
Abstract: 

 The term conservation biology tends to conjure up images of field research in remote locations and weathered-looking scientists searching for endangered species, but chalkboards, computers, and – yes - mathematics are important tools for the modern-day conservation biologist. Ecological data are often patchy and riddled with error, making it difficult to draw conclusions about the factors driving change in wildlife populations and the environment. Mathematical models can describe the mechanisms that may underlie patterns in ecological data and increase our power to test alternative hypotheses, predict future change, and evaluate the potential outcomes of different management scenarios. In an age where government and industry demand quantitative evidence before action, mathematics may be the key to conservation.

Last edited by on Fri, 04/29/2016 - 16:36

Computational Spectral Geometry: Tutorial and Modern Applications

05/06/2016 - 13:30
05/06/2016 - 14:30
Speaker: 
Justin Solomon, Princeton/MIT
Location: 
McGill, Burnside Hall, 805 Sherbrooke Str West, Room 920
Abstract: 

 This talk will be part-tutorial and part-research presentation. I will begin by summarizing some applications of spectral geometry, in particular the geometry of the Laplacian operator, appearing in the discrete geometry processing, computer graphics, and machine learning literatures. Using these applications as motivation, I will construct discretizations of the Laplacian suitable for calculations on triangulated surfaces, volumes bounded by a discretized surface, and point clouds. The talk will conclude with some of my own research in spectral geometry for constructing and analyzing maps between surfaces through the "functional maps" framework.

Last edited by on Fri, 04/29/2016 - 16:35

Une extension non commutative du théorème de Mahler sur les séries d'interpolation

05/06/2016 - 13:30
05/06/2016 - 14:30
Speaker: 
Jean-Éric Pin, LIAFA, Université Paris Diderot
Location: 
Seminar LACIM 201, av. du Président-Kennedy, LOCAL PK-4323, Montréal (Qc) H2X 3Y7
Abstract: 

 Nous donnons dans cette présentation une extension du théorème de Mahler sur les séries d'interpolation, un résultat célèbre d'analyse p-adique. Le résultat original de Mahler affirme qu'une fonction de $N$ dans $Z$ est uniformément continue pour la distance p-adique si et seulement si elle peut être uniformément approchée par des fonctions polynômes. Nous démontrons le même résultat pour les fonctions d'un monoïde libre $A*$ dans $Z$, où la distance p-adique est remplacée par la distance pro-p, la distance profinie définie sur $A*$ par les p-groupes.

Last edited by on Fri, 04/29/2016 - 16:34