| Abstract : | The astrophysical Stochastic Gravitational Wave Background (SGWB) originates from the mergers of compact binaries that are otherwise undetected as individual events, along with other sources such as supernovae, magnetars, etc. The coalescence of compact binaries in the stellar mass range can be detected by ground-based detectors (LVK, CE, ET). The number of mergers in the given interval of time is going to follow the Poissonian distribution. The Poissonian nature of the merger along with the diverse source properties will make the background signal non-stationary. The non-stationarity in the signal gives rise to the correlation of the signal at different frequencies. The structure of the signal covariance matrix can be shown to depend on the population parameters. The covariance matrix, therefore, provides additional information about the source population in addition to the power spectrum. On the other hand, the inspiraling Supermassive Black Hole Binaries (SMBHBs) radiate within the frequency range of PTA ( 10^{-9} Hz - 10^{-7} Hz). The orbits of the SMBHBs emitting in this range are very stationary on the time scale over which observations are made. However, the SGWB signal from these sources is expected to exhibit spatial anisotropy. The anisotropic SGWB will provide information about the formation channel of both SMBHs as well as their host galaxies. In this work, we have demonstrated how we can utilize the non-stationarity and anisotropy of the background signal to gain insights into the high-redshift black hole population. |
