Cosmological simulation in tides: power spectra and halo shape responses, and shape assembly bias

Understand

The well-developed separate universe technique enables accurate calibration of the response of any observable to an isotropic long-wavelength density fluctuation.

• The large-scale environment also hosts tidal modes that perturb all observables anisotropically.
• As in the separate universe, both the long tidal and density modes can be absorbed by an effective anisotropic background, on which the interaction and evolution of the short modes change accordingly.
• We further develop the tidal simulation method, including proper corrections to the second order Lagrangian perturbation theory (2LPT) to generate initial conditions of the simulations.