Mitigating half-wave plate systematics at the map-making level: calibration requirements for LiteBIRD
Abstract
Although half-wave plates (HWPs) are becoming a popular choice of polarization modulators for cosmic microwave background (CMB) experiments, their non-idealities can introduce systematic effects that should be carefully characterized and mitigated. One possible mitigation strategy is to incorporate information about the non-idealities at the map-making level, which helps to reduce the HWP-induced distortions of the reconstructed CMB. Nevertheless, the non-idealities can only be known with finite precision. In this paper we investigate the consequences of discrepancies between their true frequency profiles and those assumed by the map-maker. We present an end-to-end framework, including a blind component-separation step, and use it to translate these discrepancies into a bias on the tensor-to-scalar ratio, , for the LiteBIRD satellite mission. We subsequently derive realistic and conservative measurement requirements for accurately characterizing the HWP non-idealities to ensure they do not compromise LiteBIRD's ambitious scientific goals. We find that the obtained results are robust against sky models with varying complexity.
Cite
@article{arxiv.2602.02410,
title = {Mitigating half-wave plate systematics at the map-making level: calibration requirements for LiteBIRD},
author = {N. Raffuzzi and A. Carones and M. Monelli and S. Giardiello and L. Pagano and Y. Sakurai and H. Ishino and E. Allys and A. Anand and J. Aumont and A. J. Banday and G. Barbieri Ripamonti and R. B. Barreiro and N. Bartolo and S. Basak and A. Basyrov and A. Besnard and M. Bortolami and T. Brinckmann and F. Cacciotti and E. Calabrese and P. Campeti and F. Carralot and F. J. Casas and J. Chandran and K. Cheung and M. Citran and L. Clermont and F. Columbro and A. Coppolecchia and F. Cuttaia and P. de Bernardis and T. de Haan and M. De Lucia and P. Diego-Palazuelos and H. K. Eriksen and F. Finelli and C. Franceschet and U. Fuskeland and G. Galloni and M. Galloway and M. Gerbino and M. Gervasi and T. Ghigna and C. Gimeno-Amo and A. Gruppuso and M. Hazumi and S. Henrot-Versillé and L. T. Hergt and E. Hivon and K. Kohri and L. Lamagna and M. Lattanzi and C. Leloup and F. Levrier and A. I. Lonappan and M. López-Caniego and G. Luzzi and J. Macias-Perez and V. Maranchery and E. Martínez-González and S. Masi and S. Matarrese and T. Matsumura and S. Micheli and M. Migliaccio and G. Morgante and L. Mousset and R. Nagata and T. Namikawa and P. Natoli and A. Novelli and F. Noviello and A. Occhiuzzi and A. Paiella and D. Paoletti and G. Pascual-Cisneros and G. Patanchon and F. Piacentini and G. Piccirilli and M. Pinchera and G. Polenta and L. Porcelli and M. Remazeilles and A. Ritacco and M. Ruiz-Granda and L. Salvati and J. Sanghavi and V. Sauvage and D. Scott and M. Shiraishi and G. Signorelli and R. M. Sullivan and Y. Takase and L. Terenzi and M. Tomasi and M. Tristram and L. Vacher and B. van Tent and P. Vielva and S. Vinzl and I. K. Wehus and G. Weymann-Despres and E. J. Wollack},
journal= {arXiv preprint arXiv:2602.02410},
year = {2026}
}