Signatures of a parity-violating universe

What would a parity-violating universe look like? We present a numerical and theoretical study of mirror asymmetries in the late universe, using a new suite of N-body simulations: QUIJOTE-ODD. These feature parity-violating initial conditions, injected via a simple ansatz for the imaginary primordial trispectrum and evolved into the nonlinear regime. We find that the realization-averaged power spectrum, bispectrum, halo mass function, and matter PDF are not affected by our modifications to the initial conditions, deep into the nonlinear regime, which we argue arises from rotational and translational invariance. In contrast, the parityodd trispectrum of matter (measured using a new estimator), shows distinct signatures proportional to the parity-violating parameter, pNL, which sets the amplitude of the primordial trispectrum; furthermore, the statistic cannot be sourced by any conventional gravitational or baryonic processes. We additionally find intriguing signatures in the angular momentum of halos, with the primordial trispectrum inducing a nonzero correlation between angular momentum and smoothed velocity field, proportional to pNL. Our simulation suite has been made public to facilitate future analyses.