"Probing Primordial Parity Violation with Galaxy Intrinsic Alignments"

Abstract:

Intrinsic alignment (IA), the large-scale correlation of intrinsic galaxy and halo shapes, is recognised not only as a major systematic in weak-lensing analyses but also as a cosmological signal in its own right. Because IA is sensitive to the gravitational tidal field and its higher-order statistics, it provides information complementary to standard late-time observables and may open a new window onto early-Universe physics.

In this talk, I will present our recent analytical and numerical results on primordial parity violation in IA, combining predictions from an effective field theory for IA with measurements from N-body simulations. We show that primordial parity violation can leave distinctive signatures in the IA power spectrum. In particular, for a parity-odd trispectrum of curvature perturbations enhanced in the collapsed limit, we find a characteristic large-scale enhancement of the parity-odd component of the IA power spectrum, namely the EB power spectrum. I will then present Fisher forecasts to constrain the amplitude of such parity-violating primordial signals using current and upcoming galaxy survey data.

Everyone is warmly welcome to attend.