Lonappan, Anto IdicherianNamikawa, ToshiyaPiccirilli, G.Diego Palazuelos, PatriciaRuiz Granda, MiguelMigliaccio, M.Baccigalupi, C.Bartolo, N.Beck, D.López Caniego, MarcosEt.al.2024-08-262024-08-262024Lonappan, A. I., Namikawa, T., Piccirilli, G., Diego-Palazuelos, P., Ruiz-Granda, M., Migliaccio, M., Baccigalupi, C., Bartolo, N., Beck, D., Benabed, K., Challinor, A., Errard, J., Farrens, S., Gruppuso, A., Krachmalnicoff, N., Martínez-González, E., Pettorino, V., Sherwin, B., Starck, J., … The LiteBIRD collaboration. (2024). LiteBIRD science goals and forecasts: A full-sky measurement of gravitational lensing of the CMB. Journal of Cosmology and Astroparticle Physics, 2024(06), 009. https://doi.org/10.1088/1475-7516/2024/06/0091475-7516http://hdl.handle.net/11268/13007We 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-sky lensing map using only polarization data, even considering its limited capability to capture small-scale CMB anisotropies. In this paper, we investigate the ability to construct a full-sky lensing measurement in the presence of Galactic foregrounds, finding that several possible biases from Galactic foregrounds should be negligible after component separation by harmonic-space internal linear combination. We find that the signal-to-noise ratio of the lensing is approximately 40 using only polarization data measured over 80% of the sky. This achievement is comparable to Planck's recent lensing measurement with both temperature and polarization and represents a four-fold improvement over Planck's polarization-only lensing measurement. The LiteBIRD lensing map will complement the Planck lensing map and provide several opportunities for cross-correlation science, especially in the northern hemisphere.engAttribution 4.0 Internationalhttps://creativecommons.org/licenses/by/4.0/journal article10.1088/1475-7516/2024/06/009open accessCosmologíaActividad científicaGoal 7: Ensure access to affordable, reliable, sustainable and modern energy