Speaker: Oliver Philcox (Columbia)
Reflecting the Universe in a Mirror
Observations of the Cosmic Microwave Background (CMB) have cemented the notion that the large-scale Universe is both statistically homogeneous and isotropic. But is it invariant also under (point) reflections? Recently, observations of CMB polarization (through birefringence) and the distribution of galaxies (through four-point functions, or trispectra) have challenged this notion, and give tentative evidence for new parity-violating processes at work in the early or late Universe. In this talk, I will discuss these measurements, including their formulation and interpretation before commenting on possible explanations for the signal, both in terms of new physics and systematics. I will further discuss new analyses using the CMB temperature and polarization fluctuations, and their implications for parity violation in the Universe.
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