%0 Generic %1 chakraborty2019fullsky %A Chakraborty, Priyesh %A Pullen, Anthony R. %D 2019 %K library %T Full-Sky Lensing Reconstruction of 21 cm Intensity Maps %U http://arxiv.org/abs/1906.05873 %X Weak gravitational lensing of the 21 cm radiation is expected to be an important cosmological probe for post-reionization physics. We investigate the reconstruction of the matter density perturbations using a quadratic minimum variance estimator. The next generation of line intensity mapping (LIM) surveys such as HIRAX and CHIME will cover a larger sky fraction, which requires one to account for the curvature in the sky. Thus, we extend the plane-parallel flat-sky formalism for lensing reconstruction to account for a full-sky survey using the Spherical Fourier-Bessel (SFB) expansion. Using the HIRAX 21 cm survey as a basis, we make predictions for lensing-reconstruction noise in our formalism and compare our results with the predictions from the plane-parallel formalism. We find agreement with the plane-parallel noise power spectrum at small scales and a significant deviation at scales $L\ell_\rm res-k_eqR$ where $R$ is the radius of the shell volume, $k_eq$ is the wavenumber for matter-radiation equality, and $\ell_res$ is the angular resolution scale. Furthermore, we derive the SFB flat-sky reconstruction noise and compare it with the full-sky SFB case as well as the plane-parallel case, finding minor deviations from the full-sky noise due to sphericity. We also determine that, in the absence of non-Gaussian statistics of the intensity field but accounting for foregrounds, the signal-to-noise ratio (SNR) for $C_\ell^\phi\phi$ using our SFB estimator increases by 107%. This shows that accounting for the curved sky in LIM weak lensing will be crucial for large-scale cosmology.

@misc{chakraborty2019fullsky, abstract = {Weak gravitational lensing of the 21 cm radiation is expected to be an important cosmological probe for post-reionization physics. We investigate the reconstruction of the matter density perturbations using a quadratic minimum variance estimator. The next generation of line intensity mapping (LIM) surveys such as HIRAX and CHIME will cover a larger sky fraction, which requires one to account for the curvature in the sky. Thus, we extend the plane-parallel flat-sky formalism for lensing reconstruction to account for a full-sky survey using the Spherical Fourier-Bessel (SFB) expansion. Using the HIRAX 21 cm survey as a basis, we make predictions for lensing-reconstruction noise in our formalism and compare our results with the predictions from the plane-parallel formalism. We find agreement with the plane-parallel noise power spectrum at small scales and a significant deviation at scales $L\lesssim \ell_{\rm res}-k_{\rm eq}R$ where $R$ is the radius of the shell volume, $k_{\rm eq}$ is the wavenumber for matter-radiation equality, and $\ell_{\rm res}$ is the angular resolution scale. Furthermore, we derive the SFB flat-sky reconstruction noise and compare it with the full-sky SFB case as well as the plane-parallel case, finding minor deviations from the full-sky noise due to sphericity. We also determine that, in the absence of non-Gaussian statistics of the intensity field but accounting for foregrounds, the signal-to-noise ratio (SNR) for $C_\ell^{\phi\phi}$ using our SFB estimator increases by 107%. This shows that accounting for the curved sky in LIM weak lensing will be crucial for large-scale cosmology.}, added-at = {2019-06-17T04:52:28.000+0200}, author = {Chakraborty, Priyesh and Pullen, Anthony R.}, biburl = {https://www.bibsonomy.org/bibtex/26abdafc7b3caeb1746dc78dc90d64b72/gpkulkarni}, description = {Full-Sky Lensing Reconstruction of 21 cm Intensity Maps}, interhash = {6b11acd34cf439e6de281bf83bd0a4db}, intrahash = {6abdafc7b3caeb1746dc78dc90d64b72}, keywords = {library}, note = {cite arxiv:1906.05873Comment: 19 pages, 9 figures, submitted to MNRAS}, timestamp = {2019-06-17T04:52:28.000+0200}, title = {Full-Sky Lensing Reconstruction of 21 cm Intensity Maps}, url = {http://arxiv.org/abs/1906.05873}, year = 2019 }