Lunch talk on Dec. 9, 2024

Halo assembly bias as a probe of cluster formation and massive neutrinos

Speaker: Yunjia Song (SJTU)

Venue: SWIFAR Building 2111

Time: 12:45 PM, Monday, Dec. 9, 2024

Abstract: 

As the fossil record of the halo formation history, the internal properties of haloes (e.g., concentration) is remarkably correlated with the density environment on scales above 10 Mpc/h. This effect, commonly referred to as the halo assembly bias (HAB), is a robust prediction of the theory of structure formation within LCDM. On the one hand, HAB is an important source of systematics in cluster cosmology, especially in the modelling of the cluster weak lensing measurement; On the other hand, the magnitude of the HAB effect could be modified by the presence of massive neutrinos in the Universe, hence can be utilized as a means to probing massive neutrinos. In this talk, I will introduce our recent work in modelling HAB in cluster weak lensing and understanding the impact of massive neutrinos on HAB. I will also describe our latest effort in understanding the co-evolution between the bright central galaxy (BCG) and the halo concentration of massive clusters.

Report PPT:  SWIFAR_Yunjia_Song.pptx