# David Aldous

(University of California, Berkeley)

Conférence s'adressant à un large auditoire

Suitable for a general audience

## "What does mathematical probability tell us about the real world?"

Aside from games of chance and a handful of textbook topics (e.g. opinion polls) there is little overlap between the content of an introductory course in mathematical probability and our everyday perception of chance. In this mostly non-mathematical talk I will give some illustrations of the broader scope of probability.

Were there unusually many candidates for the 2012 Republican Presidential Nomination whose fortunes rose and fell? Why is q57c9z4A a weak password? Should you follow WolframAlpha's advice on how to divide your investments between Apple, Wal-Mart, S&P500 and bonds? Why, in a long line at airport security, do you move forward a few spaces and then wait half a minute before moving forward again? How predictable was the 2008 Global Financial Crisis?

**DATE: **Lundi 12 août 2013, 16h00 / Monday, August 12, 2013, 4:00 pm

**LIEU: ** Centre de recherches mathématiques

Pavillon André-Aisenstadt

Université de Montréal

Salle / Room 1360

*
Une réception suivra la conférence au Salon Maurice-L'abbé, Pavillon André-Aisenstadt (Salle 6245).
A reception will follow at the Salon Maurice-L'abbé, Pavillon André-Aisenstadt (Room 6245).*

Conférences dans le cadre de l'atelier "Arbres aléatoires"

Lectures at the Workshop on Random Trees

**DATE: **Mercredi 14 août 2013, 11h30 / Wednesday, August 14, 2013, 11:30 am

## "Interacting Particle Systems as Stochastic Social Dynamics"

The style of mathematical models known to probabilists as Interacting Particle Systems and exemplified by the Voter, Exclusion and Contact processes have found use in many academic disciplines. Often the underlying conceptual picture is of a social network, where individuals meet pairwise and update their "state" (opinion, activity etc) in a way depending on the two previous states. This picture motivates a precise general setup we call Finite Markov Information Exchange (FMIE) processes. The talk will briefly describe a few less familiar models (Averaging, Deference, Fashionista) suggested by the social network picture, as well as some more familiar ones.

**DATE: **Vendredi 16 août 2013, 10h30 / Friday, August 16, 2013, 10:30 am

## "The Compulsive Gambler and the Metric Coalescent"

In the Compulsive Gambler process, agents initially have equal money. When two agents with non-zero money meet, they instantly play a fair game in which one wins the other's money. The talk will describe 4 techniques that can be used to study this process in the usual n-agent setting. Moreover, by assigning agents to positions in a metric space, defining meeting rates as a function of distance, and taking the initial configuration to be a uniform distribution of unit money between agents, one can study the n-to-infinity limit 'Metric Coalescent" process which starts with a non-atomic distribution of money over the metric space.

**LIEU: **Centre de recherches mathématiques

Pavillon André-Aisenstadt

Université de Montréal

Salle / Room 6214