Title: Growing the Universe Element by Element

Sumati Surya

Writing down initial value equations seems like the norm in physics. Given initial data, we can evolve a closed classical system deterministically. Similarly, in a quantum system, given the initial wave function for a closed system, the unitary evolution gives us the wave function at any later time. But what does it mean for the universe on the whole to have a particular initial condition? And how should that be determined? In causal set theory, which is a discrete approach to quantum gravity, there is a natural choice of initial condition. I will describe these growth models — what we know about them and what we don’t.