Benchmark parameters for CMB polarization experiments

By Wayne Hu, M. Hedman, M. Zaldarriaga. 2002

179 citations recorded by the source corpus.

The recently detected polarization of the cosmic microwave background (CMB) holds the potential for revealing the physics of inflation and gravitationally mapping the large-scale structure of the universe, if so called B-mode signals below 10^{-7}, or tenths of a uK, can be reliably detected. We provide a language for describing systematic effects which distort the observed CMB temperature and polarization fields and so contaminate the B-modes. We identify 7 types of effects, described by 11 distortion fields, and show their association with known instrumental systematics such as common mode and differential gain fluctuations, line cross-coupling, pointing errors, and differential polarized beam effects. Because of aliasing from the small-scale structure in the CMB, even uncorrelated fluctuations in these effects can affect the large-scale B modes relevant to gravitational waves. Many of these problems are greatly reduced by having an instrumental beam that resolves the primary anisotropies (FWHM << 10'). To reach the ultimate goal of an inflationary energy scale of 3 \times 10^{15} GeV, polarization distortion fluctuations must be controlled at the 10^{-2}-10^{-3} level and temperature leakage to the 10^{-4}-10^{-3} level depending on effect. For example pointing errors must be controlled to 1.5'' rms for arcminute scale beams or a percent of the Gaussian beam width for larger beams; low spatial frequency differential gain fluctuations or line cross-coupling must be eliminated at the level of 10^{-4} rms.

View Paper: https://www.semanticscholar.org/paper/971d841ef2aabea39096a33539382b11df04b67a

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Citations in the corpus

Planck 2015 results. I. Overview of products and scientific results (2015, background): “Since polarization measurements are differential by nature, any mismatch in the effective beams of the detectors involved will couple with temperature anisotropies to create spurious polarization signals (Hu et al. 2003).”
Three Year Wilkinson Microwave Anistropy Probe (WMAP) Observations: Polarization Analysis (2006, unknown): “1948; Blum 1959; Faris 1967; Sault et al. 1996; Tinbergen 1996; Hu et al. 2003).”
PICO: Probe of Inflation and Cosmic Origins (2019, background): “’s a = 26value is chosen to be substantially larger than the Planck mission’s a angle (7:5) to mitigate systematic effects by scanning across each sky pixel with a greater diversity of orientations [290]. Increasing a further would decrease the Sun-shadowed volume available for the optics and conseq”
Measurements of the Temperature and E-mode Polarization of the CMB from 500 Square Degrees of SPTpol Data (2017, background): “Higher-order effects can also leak T into P , such as differential detector pointing and beam ellipticity, which add copies of the first and second derivatives of T into polarization, respectively (Hu et al. 2003).”
SPTpol: an instrument for CMB polarization measurements with the South Pole Telescope (2012, background): “Although the gravitational wave B-mode signal peaks at degree angular scales, the SPT large-aperture telescope, with 1′ resolution, offers significant advantages in reducing systematic errors generated by beam asymmetries, such as beam shape mismatches in differenced beams, which can cause T → P lea”
CMB-S4 Science Case, Reference Design, and Project Plan (2019, background): “It must achieve an accuracy of pointing knowledge while scanning that ensures sufficient control of systematic uncertainties, both in mixing of E to B modes due to pointing reconstruction errors [506] and in crossreferencing maps across SAT frequencies and with the LAT data for accurate galactic for”
New physics from the polarized light of the cosmic microwave background (2022, background): “…of detectors on the focal plane of a telescope with respect to the sky as well as cross-polarisation coupling induced by systematics of beam 284–287 and optical components such as half-wave plates 288–290 yield α , hence a spurious B -mode power spectrum, C BB , o ℓ = sin 2 ( 2 α ) C EE ℓ .”
EBEX: a balloon-borne CMB polarization experiment (2010, methodology): “Calculations based on guidelines from Hu et al.(23) show that the characterizations required for the absolute cross polarization and the instrumental polarization to insure that these systematic errors contribute negligibly to the final signal are 0.”