Special seminar

Speaker: Kwan Chuen Chan (Sun Yat-Sen University)
Title: The constraint of void bias on primordial non-Gaussianity
Date (JST): Wed, Oct 03, 2018, 15:30 - 16:30
Place: Seminar Room A
Related File: 2157.pdf
Abstract: Similar to the overdense halo counterparts, the underdense void distribution also traces the large-scale structure. Although the local primordial non-Gaussianity (PNG) model has been well constrained by Planck mission, the future large-scale structure surveys can potentially constrain it further. In the local PNG model, the large-scale scale-dependent halo bias offers a strong constraint on local PNG. Using a suit of Gaussian and PNG N-body simulations, we study the large-scale clustering of void, especially the void bias. We find that the void bias in PNG case indeed shows the characteristic scale-dependence. Since the Gaussian void bias ranges from 〜 1 to some negative values, it offers a window to constrain the PNG that is not accessible to halo clustering. Using the Fisher matrix formalism, we demonstrate that adding the scale-dependent bias information of void, the constraint on fNL can be tightened by a factor of two compared to using solely the scale-dependent bias of the halos when the tracer density >〜3*10^{-3} (Mpc/h)^{-3}.