Traditional estimators of the galaxy power spectrum and bispectrum are sensitive to survey geometry. They yield spectra that differ from true underlying signal since they convolved with window function survey. For current future generations experiments, this bias is statistically significant on large scales. It thus imperative effect summary statistics distribution accurately modelled. Moreover...

Higher-order clustering statistics, like the galaxy bispectrum, can add complementary cosmological information to what is accessible with two-point power spectrum. While standard way of measuring bispectrum involves estimating a value in large number Fourier triangle bins, compressed modal approximates as linear combination basis functions and estimates expansion coefficients on chosen basis. I...

After reionisation, the 21cm emission line of neutral hydrogen within galaxies provides a tracer dark matter. Next-generation intensity mapping surveys, with SKA and other radio telescopes, will cover large sky areas wide range redshifts, facilitating their use as probes primordial non-Gaussianity. {Previous works have shown that bispectrum can achieve tight constraints on non-Gaussianity futur...

One of the crucial aspects of density perturbations that are produced by the standard inflation scenario is that they are Gaussian where seeds produced by topological defects tend to be non-Gaussian. The three point correlation function of the temperature anisotropy of the cosmic microwave background radiation (CBR) provides a sensitive test of this aspect of the primordial density field. In th...