Anisotropies in the stochastic gravitational wave background: formalism and the cosmic string case.

We develop a powerful analytical formalism for calculating the energy density of the stochastic gravitational wave background, including a full description of its anisotropies. This is completely general, and can be applied to any astrophysical or cosmological source. As an example, we apply these tools to the case of a network of Nambu-Goto cosmic strings. We find that the anisotropies are relatively insensitive to the choice of model for the string network, but that they are very sensitive to the value of the string tension $G\mu$.