Kazhdan groups with infinite outer automorphism group

Abstract

For each countable group $Q$ we produce a short exact sequence $1\to N\to G\to Q\to 1$ where $G$ is f.g. and has a graphical $\frac{1}{6}$ presentation and $N$ is f.g. and satisfies property $T$. As a consequence we produce a group $N$ with property $T$ such that $\Out(N)$ is infinite. Using the tools developed we are also able to produce examples of nonHopfian and non-coHopfian groups with property $T$. One of our main tools is the use of random groups to achieve certain properties.

18 pages