# Zero order closed loop test of performance based scaling - BK15 regen power spectra

— C. Pryke

## Final pager

This posting is similar to 20190111_bkfinal_04bcd and previous. The goal is to make a zero order closed loop test of the sim pipeline. Noise numbers are taken from the published BK15 power spectra by Ben in 20190220_noiseparams_bk15_forS4. Without scaling for number of detector-years or sky area these are then fed into the CMB-S4 sim production machinery to make the 05.00 set using the actual BK15 hit map. These maps are then re-analyzed with the BK derived cross-spectra machinery to produce the power spectra below. Only the 95/150/220GHz bands are generated. The goal is to reproduce the BK band only $$\sigma(r)$$ value. Ben should next re-analyze these through to ML $$r$$ values alongside the standard BK15 sims - presumably using fixed $$\beta_d$$, $$\beta_\mathrm{sync}$$ etc. There may be a slight problem in that the standard BK sims do not contain any synchrotron but these do so it is not quite apples-to-apples.

The goal is to see if we get agreement of the $$\sigma(r)$$ values. We may not exactly. The standard BK sims filter out the low $$\ell$$ component and then divide out the supression resulting in increased effective $$1/f$$ noise. The S4 style sims eat this extra $$1/f$$ but do contain all low $$\ell$$ modes - so signal sample variance will be lower. The degree to which this approximation works is presumably noise level dependent. This test is only probing the specific BK15 noise level.

 Figure 1 Final Pager

### Legend for first half of the "Figure types":

• Thick red : lensed-ΛCDM scalars
• Thick black : Real data
• Colored : lensed-ΛCDM + noise + foreground realizations

### Legend for second half of the "Figure types":

#### spectra

• thick red : lensed-ΛCDM
• thin gray : s+n+f simulations with lensed-ΛCDM (sim type 5) and foregrounds (sim type 3) as signal, debiased with noise (sim type 6)
• thick gray : mean of sims (thin gray)
• red points with blue error bars : real data, debiased with the noise, uncertainties from the spread of the s+n+f sims (thin gray)

#### bp devs

• thin gray : s+n+f sims
• thin red : 1 sigma contours
• thin green : 2 sigma contours
• thick black + markers : real data
• red markers : bins that go into chi2 analysis

Note: The contours mark the simulated bandpower in each bin closest to the respective percentile.

#### chi2

• red vertical : real data
• blue : distribution from s+n+f sims
• green : chi2 probability distribution fitted to blue

#### sum bp devs

• red vertical : real data
• blue : distribution from s+n+f sims

#### uncertainties

• red : std of s+n+f sims
• blue : std of noise-only sims

Note: Remember that bandpower is a variance. Hence bandpower error bar is the std of a variance. This means noise and sample fluctuation components straight add, no quadrature — i.e. the difference between blue and red is the signal fluctatution component.