Talks

With increasingly precise measurements of the small-scale cosmic microwave background (CMB), the kinetic Sunyaev–Zel’dovich (kSZ) effect has emerged as a powerful probe of cosmology and astrophysics through cross-correlations with galaxy surveys. In this talk, I will review established applications, focusing on large-scale velocity reconstruction and its ability to test signatures of the early universe, such as primordial non-Gaussianity and compensated isocurvature perturbations. I will then introduce a new way to combine these data sets, which provides unique constraints on the distribution of ‘missing baryons’ at low redshifts, thereby opening a new window on baryonic feedback and cosmological inferences from the small-scale distribution of matter. Finally, I will explore the sensitivity of this statistic to the epoch of helium reionization, and compare its prospects to other proposed probes such as optical-depth fluctuations in the observed CMB.

Chirality is a fundamental feature of many-body physics, typically manifesting through the breaking of time-reversal symmetry. Yet a precise quantum information-theoretic characterization of chirality has remained elusive. A recent proposal defines a state as chiral if transforming it into its complex conjugate requires a circuit of large depth. Here, we rigorously establish many-body chirality for a broad family of two-dimensional stabilizer pure and mixed states. We also prove that these states are 4-partite chiral, but not 3-partite chiral.