The Computing Spacetime
  The idea that the Universe is a program in a giant quantum computer is both fascinating and suffers from various problems. Nonetheless, it can provide a unified picture of physics and this can be very useful for the problem of Quantum Gravity where such a unification is necessary. In previous work we proposed Quantum Graphity, a simple way to model a dynamical spacetime as a quantum computation. In this paper, we give an easily readable introduction to the idea of the universe as a quantum computation, the problem of quantum gravity, and the graphity models. 
Fotini Markopoulou
gr-qc