A Beginner's Guide to Numerical Relativity*

In this tutorial session I will give an overview of numerical solution of the Einstein field equations from the perspective of the Cauchy initial value problem. I will focus on difficulties central to general relativity, in particular the constraints, coordinate freedom, and singularities, and how they have been overcome for binary merger simulations. I will close with an example of an open problem where some of these challenges have yet to be solved : the interior structure of rotating  black holes formed by gravitational collapse.