The NANOGrav 15 yr Data Set: Harmonic Analysis of the Pulsar Angular
Correlations
The NANOGrav 15 yr Data Set: Harmonic Analysis of the Pulsar Angular
Correlations
Pulsar timing array observations have found evidence for an isotropic gravitational wave background with the Hellings-Downs angular correlations, expected from general relativity. This interpretation hinges on the measured shape of the angular correlations, which is predominately quadrupolar under general relativity. Here we explore a more flexible parameterization: we expand the …