| Name: Vaishali R |
| Affiliation: Raman Research Institute |
| Conference ID: ASI2026_732 |
| Title: Bayesian Inference of Quadrupolar Statistical Anisotropy in CMB |
| Abstract Type: Poster |
| Abstract Category: Galaxies and Cosmology |
| Author(s) and Co-Author(s) with Affiliation: Vaishali R(Raman Research Institute, Bengaluru - 560080, India), Hardik Jitendra Kuralkar(Raman Research Institute, Bengaluru - 560080, India), Shabbir Shaikh(Arizona State University: Tempe, Arizona, US), Tarun Souradeep(Raman Research Institute, Bengaluru- 560080, India) |
| Abstract: The Cosmic Hemispherical Asymmetry observed in the CMB commonly modelled by the Dipole modulation motivates the search for higher order statistical anisotropies using Quadrupole modulation. Violation of the rotational invariance of the primordial power spectrum can lead to non-vanishing L=2 coefficients in the Bipolar Spherical Harmonics (BipoSH), however it was shown in Planck and WMAP analyses that effects of non-circular beams also cause similar signatures. We perform Bayesian parameter inference using HMC on Planck SMICA temperature maps and FEBeCoP simulations for the Quadrupole modulation model in different multipole ranges. From the Planck PR2 map, we find that the inferred quadrupole directions are not consistent across the multipole bins. Motivated by this we then utilise the Beam-BipoSH framework to model Elliptic Gaussian beams and explore their contribution to the L=2 statistical anisotropy. |
