Speaker
Description
The standard halo model of large-scale structure provides an empirically-informed framework for describing nonlinear structures in the universe. However, this model does not enforce conservation laws, which can significantly hinder observable predictions on large scales. Examples of these observables include weak lensing, as the power spectrum is overpredicted by $\geq 8\%$ on scales larger than 20 degrees due to the absence of mass conservation, and the kinematic Sunyaev-Zel'dovich effect, where momentum conservation must be satisfied. We propose a solution to the mass conservation problem by amending the halo model to explicitly separate linear perturbations from compensated halo profiles. This amendment ensures that conservation laws are inherently satisfied and linear theory predictions are replicated on large scales. We also provide a simple fitting function for the compensated halo profiles and discuss the modified predictions for both 1-halo and 2-halo terms in the matter auto power spectrum, as well as other cosmological observables such as the weak lensing power spectrum. The results of this work are shown in more detail in https://arxiv.org/abs/1912.04872. Time permitting, I can also discuss how this model extends to the halo-mass cross power spectrum, particularly in the context of two-point halo correlations beyond the halo virial radius (https://arxiv.org/abs/2210.11499).
