Free-form reconstruction of primordial power spectrum using Planck CMB temperature and polarization

Understand

While the simplest inflationary models predict the primordial perturbations to be near scale-invariant, the primordial power spectrum (PPS) can exhibit oscillatory features in many physically well-motivated models.

• We search for hints of such features via free-form reconstructions of the PPS based on \textit{Planck} 2018 CMB temperature and polarization anisotropies.
• In order to robustly invert the oscillatory integrals and handle noisy unbinned data, we draw inspiration from image analysis techniques.
• In previous works, the Richardson-Lucy deconvolution algorithm for deblurring images has been modified for reconstructing PPS from the CMB temperature angular power spectrum.