Parity violation through CMB observations
IFPU
27-31 May 2024
This focus week will be devoted to intriguing signatures of parity violation in cosmological observables, with particular attention to their implications for cosmic microwave background (CMB) observations, like cosmic birefringence (CB). CB is a tracer of parity violating extensions of standard electromagnetism, which can be probed through cosmological observations, in particular with the CMB. Recent constraints on Planck data provide a hint of detection of the isotropic CB angle, β, at the level of 3σ C.L. or even more [1,2,3,4]. However, since the method employed to provide such an estimate, depends on the detailed knowledge of the foreground emissions, it is not clear yet whether the error budget considered in those analyses takes into account properly the systematic effects of astrophysical origin. Moreover, claims of parity violation in the 4-point correlation function (4PCF) of the BOSS galaxies have been recently published in [5,6], and tested against CMB observations [7,8] which currently are compatible with no detection, spurring a large debate. Given their important implications on fundamental physics, both the aforementioned parity-violating (hints of) signals focused a lot of attention in the cosmological community. In this meeting we wish to review recent results with a related assessment of the robustness of the analysis performed so far, review the forecasts expected in the forthcoming CMB experiments, discuss theoretical interpretations of such signals and brainstorm to set forth new ideas or new tests to stress these hints of detections.
Organisers:
- Alessandro Gruppuso (INAF, Bologna)
- Carlo Baccigalupi (SISSA, Trieste)
- Nicoletta Krachmalnicoff (SISSA, Trieste)
Participants:
- TBA