Speaker
Description
The halo model is a powerful tool for understanding the non-linear evolution of the Universe. Conventionally, a dark matter halo is defined as a virialized object according to the virial radius. However, this definition does not completely partition all mass into halos, as the halo is much more extended beyond the virial radius and grows continuously. Consequently, there is a well-known limitation of the classical halo model in the transition region between the halo edge and the large-scale environment (for about 0.1<k<1 hMpc^-1). A more accurate and explicit halo model requires a better understanding of the dark matter halo and its boundary.
In this talk, I will present an improved halo model that accounts for the unresolved mass component. Based on a new characterization of the halo boundary called depletion radius, we find the model ingredient (halo mass function, halo profile, and halo-halo correlation) can be expressed simply and naturally. I will also show how to solve for the matching halo profiles to completely decompose the matter field for any given halo catalogue. Our results show that the matching profile of the depletion-radius-based halo catalogue can be well described by the Einasto profile. Coupling the Einasto profile with the depletion-radius-based catalogue, our model accurately predicts the multiple statistics of the halo and matter field without any ad hoc fix. Finally, I will compare our model to other existing halo models, and highlight the advantages of our model in terms of clarity, interpretability, and versatility.
