# Rigidity of planar arrangements

## József Solymosi, University of British Columbia

## Date and time: 2pm, Friday, March 1, 2019

## Place: CUNY Graduate Center, Rm 4419

We will analyse various geometric problems, where we expect that
overdetermined systems have certain rigidity. For example any planar
joint-bar realization of a dense graphs has a rigid sub-framework,
unless many joints are collinear. Or, if a point-line arrangement has
many incidences, then it has a large sub-arrangement which has small
degree of freedom. We will see how such rigidity concepts might help
in solving classical problems in Discrete Geometry.