Why is computer simulation important?
Many-body problems are ubiquitous in physics, chemistry, biology, and materials science. Simulations provide a very powerful way of solving these problems, enabling one to go directly from a microscopic Hamiltonian to macroscopic properties measured in experiment, essentially without approximation. We hope to convince you of this! Some of the reasons why simulations have become so important are: • Other general methods for many-body problems involve approximations. In the continuum, a two body problem can be solved analytically. There is no exact solution for more than two bodies. • Uncontrolled approximations always breakdown somewhere. One needs a method to test out or benchmark, approximate methods to find their range of validity. This implies that the exactness of simulation is very important, otherwise we’re wasting computer and human time. • What is the role of theory today? Why not just measure properties in the lab? Simulation can give reliable predictions when experiments are
