LiteBIRD science goals and forecasts: improved full-sky reconstruction of the gravitational lensing potential through the combination of Planck and LiteBIRD data

Ruiz-Granda, M., Diego-Palazuelos, P., Gimeno-Amo, C., Vielva, P., Lonappan, A.I., Namikawa, T., Génova-Santos, R.T., Lembo, M., Nagata, R., Remazeilles, M., Adak, D., Allys, E., Anand, A., Aumont, J., Baccigalupi, C., Ballardini, M., Banday, A.J., Barreiro, R.B., Bartolo, N., Basak, S., Bersanelli, M., Besnard, A., Blinov, D., Bortolami, M., Bouchet, F., Brinckmann, T., Cacciotti, F., Calabrese, E., Campeti, P., Carones, A., Casas, F.J., Cheung, K., Citran, M., Clermont, L., Columbro, F., Coppolecchia, A., de Bernardis, P., de Haan, T., de la Hoz, E., De Lucia, M., Della Torre, S., Di Giorgi, E., Eriksen, H.K., Finelli, F., Franceschet, C., Fuskeland, U., Galloni, G., Galloway, M., Gervasi, M., Ghigna, T., Giardiello, S., Gruppuso, A., Hazumi, M., Hergt, L.T., Hivon, E., Ichiki, K., Jiang, H., Jost, B., Kohri, K., Lamagna, L., Lattanzi, M., Leloup, C., Levrier, F., López-Caniego, M., Luzzi, G., Macias-Perez, J., Maranchery, V., Martínez-González, E., Masi, S., Matarrese, S., Matsumura, T., Micheli, S., Monelli, M., Montier, L., Morgante, G., Najafi, M., Novelli, A., Noviello, F., Obata, I., Occhiuzzi, A., Paiella, A., Paoletti, D., Pascual-Cisneros, G., Piacentini, F., Piccirilli, G., Polenta, G., Porcelli, L., Raffuzzi, N., Rizzieri, A., Rubiño-Martín, J.A., Sakurai, Y., Sanghavi, J., Scott, D., Shiraishi, M., Signorelli, G., Sullivan, R.M., Takase, Y., Terenzi, L., Tomasi, M., Tristram, M., Vacher, L., van Tent, B., Wehus, I.K., Weymann-Despres, G., Zhou, Y. and undefined, undefined 2025. LiteBIRD science goals and forecasts: improved full-sky reconstruction of the gravitational lensing potential through the combination of Planck and LiteBIRD data. Journal of Cosmology and Astroparticle Physics 11 (2025) , 073. 10.1088/1475-7516/2025/11/073

Full text not available from this repository.

Abstract

Cosmic microwave background (CMB) photons are deflected by large-scale structure through gravitational lensing. This secondary effect introduces higher-order correlations in CMB anisotropies, which are used to reconstruct lensing deflections. This allows mapping of the integrated matter distribution along the line of sight, probing the growth of structure, and recovering an undistorted view of the last-scattering surface. Gravitational lensing has been measured by previous CMB experiments, with Planck's 42 σ detection being the current best full-sky lensing map. We present an enhanced LiteBIRD lensing map by extending the CMB multipole range and including the minimum-variance estimation, leading to a 49 to 58 σ detection over 80 % of the sky, depending on the final complexity of polarized Galactic emission. The combination of Planck and LiteBIRD will be the best full-sky lensing map in the 2030s, providing a 72 to 78 σ detection over 80 % of the sky, almost doubling Planck's sensitivity. Finally, we explore different applications of the lensing map, including cosmological parameter estimation using a lensing-only likelihood and internal delensing, showing that the combination of both experiments leads to improved constraints. The combination of Planck + LiteBIRD will improve the S8 constraint by a factor of 2 compared to Planck, and Planck + LiteBIRD internal delensing will improve LiteBIRD's tensor-to-scalar ratio constraint by 6 %. We have tested the robustness of our results against foreground models of different complexity, showing that improvements remain even for the most complex foregrounds.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Schools > Physics and Astronomy
Publisher:	IOP Publishing
Date of Acceptance:	8 October 2025
Last Modified:	08 Dec 2025 14:31
URI:	https://orca.cardiff.ac.uk/id/eprint/182977

Actions (repository staff only)

Edit Item