Lunch talk on Aug. 26, 2026

Searching for Cosmological Parity Violation with Composite-field Trispectrum Estimators

Speaker: Zucheng Gao (CNRS)

Venue: SWIFAR Building 2111

Time: 12:45 PM, Wednesday, Aug. 26, 2026

Abstract: 

Parity violation in large-scale structure would provide a distinctive signature of physics beyond the standard cosmological model. For the scalar galaxy density field, the leading parity-odd signal arises in the four-point function, whose high dimensionality makes direct measurement challenging. I will present parity-odd kurto spectra, a set of power-spectrum-like observables that compress the galaxy trispectrum into efficient one-dimensional estimators. I will describe their theoretical construction, validation using perturbative fields and N-body simulations, and sensitivity to stochasticity, survey volume and tracer density. I will then present their application to BOSS DR12 and DESI DR1 luminous red galaxies. Although we find no significant evidence for parity violation, DESI already provides substantially improved precision and demonstrates the potential of compressed higher-order statistics for testing fundamental symmetries.