#### Alladi Ramakrishnan Hall

#### Four Cycle Free Graphs and Entropy Minimality

#### Nishant Chandgotia

##### University of British Columbia

*A topological dynamical system (X,T) is said to be entropy minimal if
all closed T-invariant subsets of X have entropy strictly less than
(X,T). <>In this talk we will discuss the entropy minimality of a
class of topological dynamical systems which appear as the space of
graph homomorphisms from Z^d to graphs without four cycles; for
instance, we will see why the space of 3-colourings of Z^d is entropy
minimal even though it does not have any of the nice topological
mixing properties.*

Done