The many faces of percolation

Date

Feb 11, 2013

Time

4:30 PM - 5:30 PM

Speaker

Peter Grassberger

Affiliation

University of Calgary

Series

MPI-PKS Kolloquium

Language

en

Main Topic

Physik

Other Topics

Physik

Host

Eduardo Altmann

Description

A few years ago, percolation theory was considered a mature subject holding few surprises, but recent progress has changed this radically. While "ordinary" percolation shows a second order phase transition between two phases with and without long range connectivity as local connections are increased, examples have now been found where this transition can range from infinite order to first order. The latter is of particular importance in social sciences, where first order percolation transitions show up as a consequence of synergistic effects, and I will point out their close relationship with rough interfaces in condensed matter physics. Another case where first order percolation transitions show up is interdependent networks, although first claims about this have to be substantially modified -- in some cases of interdependent networks the transition is second order but in a new universality class. The very notion of universality classes has been questioned for "Achleoptas processes", and blatant violations of universality have been observed in "agglomerative percolation", where it is related to a symmetry breaking transition coinciding with the percolation transition.

Last modified: Feb 5, 2013, 9:03:19 AM