Aarhus University Seal / Aarhus Universitets segl

Social choice and topology

Simon Stoltze
Foredrag for studerende
Fredag, 26 september, 2014, at 15:15-16:00, in Aud. D4 (1531-219)
The theory of social choice deals with the problem of holding a
'fair' election in a society, i.e. combining individual opinions
into a collective choice. One of the famous results of this theory is
'Arrow's impossibility theorem' which (loosely) states that it is
impossible to have a fair election.

It turns out that with minor assumptions, finding a fair
choice-function turns into a problem well-suited for algebraic
topology. This can be used to say something about what is needed to
have a fair election and gives rise to some counter-intuitive results.

In the talk, I will talk about classical social choice theory and state
Arrow's theorem before moving on to the topological side of
things. The first part should be accessible to everyone while the
second will require basic knowledge of groups and some facts from
algebraic topology that I will state but not prove.
Kontaktperson: Thomas Lundsgaard Schmidt