Assembly bias in quadratic bias parameters of dark matter halos from forward modeling

Understand

We use the forward modeling approach to galaxy clustering combined with the likelihood from the effective-field theory of large-scale structure to measure assembly bias, i.e.

• the dependence of halo bias on properties beyond the total mass, in the linear ($b_1$) and second order bias parameters ($b_2$ and $b_{K^2}$) of dark matter halos in $N$-body simulations.
• This is the first time that assembly bias in the tidal bias parameter $b_{K^2}$ is measured.
• We focus on three standard halo properties: the concentration $c$, spin $\lambda$, and sphericity $s$, for which we find an assembly bias signal in $b_{K^2}$ that is opposite to that in $b_1$.