Overview of the medium and high frequency telescopes of the LiteBIRD space mission

We present novel realizations of Higgs inflation within Supergravity which are largely tied to the existence of a pole of order two in the kinetic term of the inflaton field. This pole arises due to the selected s which parameterize the (SU(1,1)/U(1))2 or SU(2,1)/(SU(2) × U(1)) manifolds with scalar curvatures ℛ(11)2 =-4/N or ℛ21=-3/N respectively. The associated superpotential includes, in addition to the Higgs superfields, a stabilizer superfield, respects the gauge and an R symmetries and contains the first allowed nonrenormalizable term. If the coefficient of this term is almost equal to that of the others within about 10-5 and N=1, the inflationary observables can be done compatible with the present data and the scale M of gauge-symmetry breaking may assume its value within MSSM. Increasing M beyond this value, though, inflation may be attained with less tuning. Modifications to the Kähler potentials associated with the manifolds above allow for inflation, realized with just renormalizable superpotential terms, which results to higher tensor-to-scalar ratios as N approaches its maximum at N ≃ 40.

Section: Himentioning

confidence: 68%

Section: Introductionmentioning

confidence: 99%

Pole-induced Higgs inflation with hyperbolic Kähler geometries

Pallis¹

2021

“…The LiteBIRD satellite includes three telescopes at low, medium, and high frequencies (LFT [20], MFT and HFT [21]). With an aperture diameter of 400 mm and an angular resolution ranging from 71 to 24 arcmin, the LFT includes nine frequency bands, three of them redundant making twelve channels within the LFT, distributed from the lower bound of the lowest frequency channel at 34 GHz to the upper bound of the highest frequency channel at 161 GHz, in order to cover the spectral domains of both CMB and low frequency Galactic emission.…”

Section: Overview Of Litebirdmentioning

confidence: 99%

“…are detailed in table 1. Figure 1 shows the integration of the LFT, MFT and HFT on the LiteBIRD satellite [20,21].…”

Section: Overview Of Litebirdmentioning

confidence: 99%

Impact of beam far side-lobe knowledge in the presence of foregrounds for LiteBIRD

Leloup,

Patanchon,

Errard

et al. 2024

We present a study of the impact of a beam far side-lobe lack of knowledge on the measurement of the Cosmic Microwave Background B-mode signal at large scale. Beam far side-lobes induce a mismatch in the transfer function of Galactic foregrounds between the dipole and higher multipoles which degrads the performances of component separation methods. This leads to foreground residuals in the CMB map. It is expected to be one of the main source of systematic effects in future CMB polarization observations. Thus, it becomes crucial for all-sky survey missions to take into account the interplays between beam systematic effects and all the data analysis steps. LiteBIRD is the ISAS/JAXA second strategic large-class satellite mission and is dedicated to target the measurement of CMB primordial B modes by reaching a sensitivity on the tensor-to-scalar ratio r of σ(r) ≤ 10-3 assuming r = 0. The primary goal of this paper is to provide the methodology and develop the framework to carry out the end-to-end study of beam far side-lobe effects for a space-borne CMB experiment. We introduce uncertainties in the beam model, and propagate the beam effects through all the steps of the analysis pipeline, most importantly including component separation, up to the cosmological results in the form of a bias δr. As a demonstration of our framework, we derive requirements on the calibration and modeling for the LiteBIRD's beams under given assumptions on design, simulation, component separation method and allocated error budget. In particular, we assume a parametric method of component separation with no mitigation of the far side-lobes effect at any stage of the analysis pipeline. We show that δr is mostly due to the integrated fractional power difference between the estimated beams and the true beams in the far side-lobes region, with little dependence on the actual shape of the beams, for low enough δr. Under our set of assumptions, in particular considering the specific foreground cleaning method we used, we find that the integrated fractional power in the far side-lobes should be known at the level of ∼ 10-4, to achieve the required limit on the bias δr < 1.9 × 10-5. The framework and tools developed for this study can be easily adapted to provide requirements under different design, data analysis frameworks and for other future space-borne experiments, such as PICO or CMB-Bharat. We further discuss the limitations of this framework and potential extensions to circumvent them.

“…Each telescope consists of a continuously rotating HWP, an optical system (cross-Dragone for LFT, and two two-lens refractor systems for MFT and HFT), thermal filters, and a focal plane [62,63]. Each focal plane contains an array of wafers and each wafer contains multiple beam-forming elements.…”

Section: Polarization Angle Offsetsmentioning

confidence: 99%

In-flight polarization angle calibration for LiteBIRD: blind challenge and cosmological implications

Krachmalnicoff

Matsumura

Hoz

et al. 2022

We present a demonstration of the in-flight polarization angle calibration for the JAXA/ISAS second strategic large class mission, LiteBIRD, and estimate its impact on the measurement of the tensor-to-scalar ratio parameter, r, using simulated data. We generate a set of simulated sky maps with CMB and polarized foreground emission, and inject instrumental noise and polarization angle offsets to the 22 (partially overlapping) LiteBIRD frequency channels. Our in-flight angle calibration relies on nulling the EB cross correlation of the polarized signal in each channel. This calibration step has been carried out by two independent groups with a blind analysis, allowing an accuracy of the order of a few arc-minutes to be reached on the estimate of the angle offsets. Both the corrected and uncorrected multi-frequency maps are propagated through the foreground cleaning step, with the goal of computing clean CMB maps. We employ two component separation algorithms, the Bayesian-Separation of Components and Residuals Estimate Tool (B-SeCRET), and the Needlet Internal Linear Combination (NILC). We find that the recovered CMB maps obtained with algorithms that do not make any assumptions about the foreground properties, such as NILC, are only mildly affected by the angle miscalibration. However, polarization angle offsets strongly bias results obtained with the parametric fitting method. Once the miscalibration angles are corrected by EB nulling prior to the component separation, both component separation algorithms result in an unbiased estimation of the r parameter. While this work is motivated by the conceptual design study for LiteBIRD, its framework can be broadly applied to any CMB polarization experiment. In particular, the combination of simulation plus blind analysis provides a robust forecast by taking into account not only detector sensitivity but also systematic effects.