We explore the capability of measuring lensing signals in LiteBIRD full-sky polarization maps.With a 30 arcmin beam width and an impressively low polarization noise of 2.16 μK-arcmin,LiteBIRD will be able to measure the full-sky polarization of the cosmic microwave background (CMB)very precisely. This unique sensitivity also enables the reconstruction of a nearly full-skylensing map using only polarization data, even considering its limited capability to capturesmall-scale CMB anisotropies. In this paper, we investigate the ability to construct a full-skylensing measurement in the presence of Galactic foregrounds, finding that several possible biasesfrom Galactic foregrounds should be negligible after component separation by harmonic-spaceinternal linear combination. We find that the signal-to-noise ratio of the lensing isapproximately 40 using only polarization data measured over 80% of the sky. Thisachievement is comparable to Planck's recent lensing measurement with both temperature andpolarization and represents a four-fold improvement over Planck's polarization-only lensingmeasurement. The LiteBIRD lensing map will complement the Planck lensing map and provide severalopportunities for cross-correlation science, especially in the northern hemisphere.
LiteBIRD science goals and forecasts: a full-sky measurement of gravitational lensing of the CMB
Migliaccio, M.;Baccigalupi, C.;Gruppuso, A.;Krachmalnicoff, N.;Ballardini, M.;Bortolami, M.;Brinckmann, T.;Campeti, P.;Finelli, F.;Galloni, G.;Gerbino, M.;Giardiello, S.;Lattanzi, M.;Lembo, M.;Matarrese, S.;Natoli, P.;Pagano, L.;Paoletti, D.;
2024
Abstract
We explore the capability of measuring lensing signals in LiteBIRD full-sky polarization maps.With a 30 arcmin beam width and an impressively low polarization noise of 2.16 μK-arcmin,LiteBIRD will be able to measure the full-sky polarization of the cosmic microwave background (CMB)very precisely. This unique sensitivity also enables the reconstruction of a nearly full-skylensing map using only polarization data, even considering its limited capability to capturesmall-scale CMB anisotropies. In this paper, we investigate the ability to construct a full-skylensing measurement in the presence of Galactic foregrounds, finding that several possible biasesfrom Galactic foregrounds should be negligible after component separation by harmonic-spaceinternal linear combination. We find that the signal-to-noise ratio of the lensing isapproximately 40 using only polarization data measured over 80% of the sky. Thisachievement is comparable to Planck's recent lensing measurement with both temperature andpolarization and represents a four-fold improvement over Planck's polarization-only lensingmeasurement. The LiteBIRD lensing map will complement the Planck lensing map and provide severalopportunities for cross-correlation science, especially in the northern hemisphere.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
