  In the last years many results in the area of semidefinite programming were
obtained for invariant (finite dimensional, or infinite dimensional)
semidefinite programs - SDPs which have symmetry. This was done for a variety
of problems and applications. The purpose of this handbook chapter is to give
the reader the necessary background for dealing with semidefinite programs
which have symmetry. Here the basic theory is given and it is illustrated in
applications from coding theory, combinatorics, geometry, and polynomial
optimization.
