UMICH-2015: CMB-Lensing Summary

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Lensing noise.jpg

  • Lensing maps will be sample variance limited over broad range in L

Which modes.jpg

  • Lensing B-modes come from a range in E modes
  • Lensing phi-reconstruction on different scales have different demands on E/B measurements


  • Delensing needs to be done

Delensing methods.jpg

  • Quadratic estimator delensing leaves some contamination

Lensing lensing.jpg

  • CMB lensing & cosmic shear with galaxies are nicely complementary
    • measure calibration biases in galaxy shear
    • different probe of galaxy shape intrinsic alignments from large-scale tidal fields (same tidal fields cause CMB lensing)

Action items

  • "Be better"
    • quadratic estimators are not enough, need to do either something iterative or something using sampling
  • Propagate missing modes (i.e., anisotropic noise, E/B separation, etc.) & foregrounds into delensing
    • write down the matrix magic which does this
  • Foregrounds
    • are there any issues with radio point sources or Galactic dust?
    • general foreground bispectra & trispectra can be measured to inform possible contamination of lensing reconstructions
    • e.g., simulate toy model for high-ell polarized dust through lensing estimator
  • revisit cmbpol systematics estimates with S4 sensibilities
  • Forecast CMB lensing-galaxy lensing x-corr exploring intrinsic alignments, shear calibration biases
  • Forecast CMB lensing-galaxy clustering x-corr for neutrino masses
  • Forecast galaxy cluster mass measurement accuracy for different beam size & sensitivity [CMB lensing & how many clusters]
    • pol-only to avoid SZ, or multifrequency?