Combining Systematic Effects in CMB Polarization Experiments through map-based simulations: application to LiteBIRD's HWP non-idealities and detectors non-linearity
Year: 2026
Type: preprint
Abstract: We quantify the impact of coupled instrumental systematics on next-generation CMB polarization experiments targeting primordial $B$-mode polarization, with a focus on the forthcoming \textit{LiteBIRD} satellite mission. We study the interplay between the non-linear response of Transition-Edge Sensor (TES) bolometers and Half-Wave Plate (HWP) non-idealities, in particular synchronous signals arising from differential emissivity. We develop a map-based formalism that captures the resulting intensity-to-polarization leakage by explicitly solving the binning map-making equations, avoiding the need for computationally expensive time-ordered data simulations. We apply this framework to \textit{LiteBIRD}, adopting its baseline scanning strategy and frequency configuration, and perform analyses at both single- and multi-frequency levels, including Galactic foregrounds and blind component separation. We find that while detector non-linearity and HWP non-idealities individually induce negligible bias on the tensor-to-scalar ratio $r$, their coupling can generate non-trivial contamination, driven by large signals such as the solar dipole and amplified in high-frequency channels by foreground leakage. From these results, we derive joint requirements on detector non-linearity and HWP differential emission, and discuss their implications for the instrument design and calibration strategy of \textit{LiteBIRD} and future CMB polarization missions targeting $r \lesssim 10^{-3}$.
Source: arXiv (Cornell University)
Institutions: Istituto Nazionale di Fisica Nucleare, Sezione di Roma I, Sapienza University of Rome, High Energy Accelerator Research Organization, Kavli Institute for the Physics and Mathematics of the Universe, International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles, The University of Tokyo, Scuola Internazionale Superiore di Studi Avanzati, Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, University of Milano-Bicocca
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: U.S. Department of Energy, National Aeronautics and Space Administration, UK Space Agency, European Commission, Deutsche Forschungsgemeinschaft, Ministry of Education, Culture, Sports, Science and Technology, Swedish National Space Agency, Centro para el Desarrollo Tecnológico Industrial, Centre National d’Etudes Spatiales, Centre National de la Recherche Scientifique, Japan Society for the Promotion of Science, Japan Aerospace Exploration Agency, Agencia Estatal de Investigación
OpenAlex ID: W7206156338