High-Redshift Dark Matter Halo Bias from the GUREFT Simulations

The clustering of dark matter halos is a key ingredient in connecting observations to the underlying cosmology. While halo bias has been extensively studied at low redshift, its high-redshift behavior remains comparatively poorly understood. This gap is becoming increasingly important as new and upcoming deep surveys—such as JWST, Roman, HERA, and SKA —are making precision measurements of large-scale clustering at early cosmic times feasible. Before using these measurements to place tensions on the standard cosmological model, it is essential to understand how structure formation behaves within the model itself in this regime. In this talk, I present measurements of dark matter halo bias at high redshift using the recently developed GUREFT simulations, which are specifically designed to meet the needs of high-redshift studies. I compare these measurements against commonly used fitting functions calibrated at low redshift, and discuss implications for interpreting forthcoming high-redshift clustering data.