Minimum variance estimation of statistical anisotropy via galaxy survey

We consider the benefits of measuring cosmic statistical anisotropy from redshift-space correlators galaxy number density fluctuation and peculiar velocity field without adopting plane-parallel (PP) approximation. Since are decomposed using general tripolar spherical harmonic (TripoSH) basis, we can deal with wide-angle contributions untreatable by PP approximation, at same time, target anisotropic signatures be cleanly extracted. We, for first compute covariance TripoSH decomposition coefficient Fisher matrix to forecast detectability anisotropy. The resultant expression is free nontrivial mixings between each multipole moment caused approximation hence fully optimized. Compared analysis under superiority in always confirmed, it highlighted, especially cases that shot noise level large has a blue-tilted shape Fourier space. application TripoSH-based forthcoming all-sky survey data could result constraints on comparable or tighter than current microwave background ones.