Tutte seminar - Britta Peis - cancelled

Friday, December 12, 2014 3:30 pm - 3:30 pm EST (GMT -05:00)

Resource Competition on Matroids

Speaker: Britta Peis
Affiliation: RWTH Aachen University
Room: M3 3103

Abstract:  

Congestion games are widely used to model and analyse the behaviour of selfish acting uncontrolled individuals competing over a commonly used set of resources. A typical example of congestion games can be observed every day at rush hour in a congested city: each individual car driver chooses a route through a street network. The travel time of each of the streets ("resources") in use highly depends on the congestion caused by the route choices of the other car drivers.
A stable state ("equilibrium") is reached if none of the individuals can improve its outcome by unilateral switching to an alternative route ("strategy"). The famous Braess paradox describes the interesting phenomenon that improving the network infrastructure, for example by building new streets, may in fact lead to higher travel times under an equilibrium. Game theory now investigates under which conditions equilibria exist, are efficient, and admit a Braess paradox. As it turns out, structural properties and algorithmic techniques from combinatorial optimization can be extremely helpful for such investigations. For example, as will be shown in the talk, matroids are the only structures that are immune to Braess paradox, and that guarantee the existence of equilibria for several variants of congestion games. (Joint work with Tobias Harks.)