UMICH-2015: Neutrino and Light Relativisic Species break-out session 2

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Clear science target is measuring Mnu to 3\sigma with minimum mass case of ~0.058eV.

Main observable: CMB lensing. Other observables: SZ cluster abundance, cluster momentum (arXiv:1412.0592), ...

From 1402.4108 and 1309.5383 S4 can’t detect Mnu = 0.058 eV without external datasets (BAO, galaxy clustering. . . ). But with external datasets (DESI) S4 forecasted to get 3-4\sigma detection. NB: DESI + Planck forecasted to reach this already.

What is needed to be certain that neutrino mass can be detected at high significance?

  • How large are theoretical uncertainties in modeling nonlinear evolution and baryonic effects on P(k)?
  • Degeneracies with inflationary parameters? Degeneracies with dark energy?
  • What sensitivity, resolution, sky coverage is needed? (1402.4108 says > 10^5 detectors, fsky > 0.25, \approx 1 muK-arcmin and not very sensitive to resolution for beam size < 4’ — are these numbers stable to theoretical & astrophysical uncertainties?) (A.M) also do we need to go beyond Fisher Matrces? I am always a bit worried when parameters increase and degeneracies became so important.
  • How well do astrophysical foregrounds or other systematics in measuring C_{\Phi\Phi} need to be controlled? (A.M) VAN ENGELEN et al. 1310.7023 is a good starting point what else need to be explored before S4?

Optimistic thoughts:

  • With S4 + external datasets can we measure more than just Mnu? (i.e. any info on individual masses, or other cross-checks of standard CnuB?)

Slides