The $N_\ell$ of gravitational wave background experiments

Understand

We construct a model for the angular power spectrum of the instrumental noise in interferometer networks mapping gravitational wave backgrounds (GWBs) as a function of detector noise properties, network configuration and scan strategy.

• We use the model to calculate the noise power spectrum for current and future ground-based experiments, as well as for planned space missions.
• We present our results in a language similar to that used in cosmic microwave background and intensity mapping experiments, and connect the formalism with the sensitivity curves that are common lore in GWB analyses.
• Our formalism is implemented in a lightweight python module that we make publicly available at https://github.com/damonge/schNell.