The Simons Observatory: Combining delensing and foreground cleaning for improved constraints on inflation

Kavli Affiliate: Toshiya Namikawa

| First 5 Authors: Emilie Hertig, Kevin Wolz, Toshiya Namikawa, Antón Baleato Lizancos, Susanna Azzoni

| Summary:

The Simons Observatory (SO), a next-generation ground-based CMB experiment in
its final stages of construction, will target primordial $B$-modes with
unprecedented sensitivity to set tight bounds on the amplitude of inflationary
gravitational waves. Aiming to infer the tensor-to-scalar ratio $r$ with
precision $sigma(r=0) leq 0.003$, SO will rely on powerful
component-separation algorithms to distinguish the faint primordial signal from
stronger sources of large-scale $B$-modes such as Galactic foregrounds and weak
gravitational lensing. We present an analysis pipeline that performs delensing
and foreground cleaning simultaneously by including multifrequency CMB data and
a lensing $B$-mode template in a power-spectrum-based likelihood. Here, we
demonstrate this algorithm on masked SO-like simulations containing
inhomogeneous noise and non-Gaussian foregrounds. The lensing convergence is
reconstructed from high-resolution simulations of the CMB and external mass
tracers. Using optimized pixel weights for power spectrum estimation, the
target precision for SO’s nominal design is achieved and delensing reduces
$sigma(r)$ by 27-37%, depending on foreground complexity.

| Search Query: ArXiv Query: search_query=au:”Toshiya Namikawa”&id_list=&start=0&max_results=3

Read More