When: Wednesday, September 27, 2023, 7:30 PM - 9:00 PMWhere: Physics (G. O. Jones building) Room 516, Mile End
Speaker: Wuhyun Sohn (KASI)
While the simplest inflation model is consistent with current observations, numerous well-motivated early universe models predict some oscillations in the primordial power spectrum and bispectrum. We present our recent works on studying primordial features and non-Gaussianity using CMB data. First, we search for hints of features in the primordial power spectrum via an iterative free-form reconstruction method and genetic algorithms. The statistical significance of the features is then tested using mock data. Second, we present CMB-BEST, a publicly available code for getting Planck CMB bispectrum constraints on primordial non-Gaussianity for any given bispectrum shape in seconds. The code is applied to study some highly oscillatory bispectrum templates that were previously out of reach, to put constraints on a model of a scalar-tensor theory, and to allow joint analysis in combination with power spectrum likelihood within the framework of Cobaya. We summarise that, while there is no concrete evidence of primordial features or non-Gaussianity, they still remain viable and will be constrained with upcoming CMB surveys.