Universality in spin systems

I will talk about a notion of universality in spin systems by which certain spin systems can simulate all others. We provide sufficient and necessary conditions for a spin system to be universal, and show that the Ising model and many other “simple” systems are universal. This notion of universality is somewhat similar to the notion of universality in computer science (by which there exist universal Turing machines) — I will mention ongoing work in trying to make this connection precise.