Difference between revisions of "UMICH-2015: Inflation break-out session 1"

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===Foregrounds===
 
===Foregrounds===
  
*What are our latest estimates of foreground levels post-Planck? (Steve, Raphael...)
+
*'''What are our latest estimates of foreground levels post-Planck? (Steve, Raphael...)'''
  
 
Figure from Steve Choi/Lyman Page:
 
Figure from Steve Choi/Lyman Page:
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*What simulations and tools do we have for forecasting impact on r? (Jacques, Raphael, Stephen F, Aurelien, Jo) - detailed discussion on Tuesday
+
'''What simulations and tools do we have for forecasting impact on r? (Jacques, Raphael, Stephen F, Aurelien, Brendan, Jo) - detailed discussion on Tuesday
 +
 
 +
*Does a new PSM exist right now? http://www.apc.univ-paris7.fr/~delabrou/PSM/psm.html. Common sim maps would be great.
 +
 
 +
*'''[paraphrasing Aurelien]''' Addressing questions about model uncertainty requires a flexible simulation facility, which can be easily modified and run by everyone for a wide range of parameters, and interfaced with current analysis and forecasting pipelines.  Ideally would use modern python tools and have mechanism for the community to efficiently contribute to its development and easily make and share his/her own simulations using a common infrastructure.  PSM is great, how do we make the best use of it as a starting point.
 +
 
 +
*'''[Paraphrasing Brendan]''' had a problem using the PSM during the BKP analysis – because the dust polarization model in the PSM comes from a filtered version of Planck 353, it includes Planck noise, and there is nowhere in the PSM sky that is as clean as dust as the real Bicep region
 +
 
 +
*We still still want ability to do quick and dirty Fisher forecasts for exploring different set-ups, so still want quick ways to inflate Nl for example.
 +
 
  
Is there a new PSM? http://www.apc.univ-paris7.fr/~delabrou/PSM/psm.html. Common sim maps would be great. Ability to do quick and dirty forecasts always good for exploring different set-ups.
 
  
 
-----
 
-----
*What are still physical unknowns? (Al Kogut?)
+
'''What are still physical unknowns?'''
 +
 
 +
*They include magnetic dust, spinning dust polarization, spatial dispersion of dust temperature/emissivity...
  
Magnetic dust, spinning dust polarization, spatial dispersion of dust temperature/emissivity...
+
*(Brendan) At what point we think that the greybody model for dust emission will break down?
 +
 
 +
*Don't yet know enough from Planck: dispersion in dust index between individual 300 deg2 patches is about +-0.15 and varies between beta = 1.1 and 2.2.
 +
 
 +
*Al Kogut has done sims for PIXIE to look at possible residuals given varying dust temperature
  
From Planck, dispersion in dust index between individual 300 deg2 patches is about +-0.15 and varies between beta = 1.1 and 2.2.
 
 
-----
 
-----
*Do we need new data at <40 GHz and >230-300 GHz? (Clem/John?, Mark)
+
*Do we need new data at <40 GHz and >230-300 GHz? And what about 60GHz? (Clem,John, Aurelien, Jo)
  
 
The effective polarized noise from cleaning 150 GHz with Planck 353 GHz  is about 19 uK-arcmin, i.e. an additional sigma(r) ~0.01 for fsky=0.2
 
The effective polarized noise from cleaning 150 GHz with Planck 353 GHz  is about 19 uK-arcmin, i.e. an additional sigma(r) ~0.01 for fsky=0.2
 +
 +
[[File:bkp_fig13.png|500px]]
  
 
[[File:index.png|500px]]
 
[[File:index.png|500px]]
 +
 +
*'''Aurelien'''': For 60 GHz, want something there in the long term to understand dust / synchrotron correlations.  But in the medium term, how well can we do without it? 
  
 
-----
 
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*How important is large sky area?
+
'''How important is large sky area?'''
  
 
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 +
'''What is the path to make convincing detection of B-modes'''
  
 
===Delensing===  
 
===Delensing===  

Revision as of 08:13, 20 September 2015

Wiki navigation

B-modes challenges: foregrounds and de-lensing

Return to main workshop page

Return to Inflation sessions page


Foregrounds

  • What are our latest estimates of foreground levels post-Planck?
  • What simulations and tools do we have for forecasting impact on r? (details for Tuesday)
  • What are still physical unknowns?
  • Do we need new data at <40 GHz and >230 GHz? (and 60 GHz?)
  • How important is large sky area?
  • What is the path to a convincing claim that a B-mode signal is not foregrounds?

Delensing

  • What is the impact of delensing on r, and on nt or BB wiggles?
  • How does internal CMB delensing compare to external (e.g. CIB)?
  • What sensitivity and resolution do we need for the lensing map?

Foregrounds

  • What are our latest estimates of foreground levels post-Planck? (Steve, Raphael...)

Figure from Steve Choi/Lyman Page:

Choi.png

Can we make a new version of this figure:

OldFG.png


What simulations and tools do we have for forecasting impact on r? (Jacques, Raphael, Stephen F, Aurelien, Brendan, Jo) - detailed discussion on Tuesday

  • [paraphrasing Aurelien] Addressing questions about model uncertainty requires a flexible simulation facility, which can be easily modified and run by everyone for a wide range of parameters, and interfaced with current analysis and forecasting pipelines. Ideally would use modern python tools and have mechanism for the community to efficiently contribute to its development and easily make and share his/her own simulations using a common infrastructure. PSM is great, how do we make the best use of it as a starting point.
  • [Paraphrasing Brendan] had a problem using the PSM during the BKP analysis – because the dust polarization model in the PSM comes from a filtered version of Planck 353, it includes Planck noise, and there is nowhere in the PSM sky that is as clean as dust as the real Bicep region
  • We still still want ability to do quick and dirty Fisher forecasts for exploring different set-ups, so still want quick ways to inflate Nl for example.



What are still physical unknowns?

  • They include magnetic dust, spinning dust polarization, spatial dispersion of dust temperature/emissivity...
  • (Brendan) At what point we think that the greybody model for dust emission will break down?
  • Don't yet know enough from Planck: dispersion in dust index between individual 300 deg2 patches is about +-0.15 and varies between beta = 1.1 and 2.2.
  • Al Kogut has done sims for PIXIE to look at possible residuals given varying dust temperature

  • Do we need new data at <40 GHz and >230-300 GHz? And what about 60GHz? (Clem,John, Aurelien, Jo)

The effective polarized noise from cleaning 150 GHz with Planck 353 GHz is about 19 uK-arcmin, i.e. an additional sigma(r) ~0.01 for fsky=0.2

Bkp fig13.png

Index.png

  • Aurelien': For 60 GHz, want something there in the long term to understand dust / synchrotron correlations. But in the medium term, how well can we do without it?

How important is large sky area?


What is the path to make convincing detection of B-modes

Delensing

(Blake Sherwin, Olivier Dore, Chris Sheehy, Josquin Errard, Stephen Feeney, Alex van Engelen, Neelima Sehgal, Anthony Challinor...)

  • What is the impact of delensing on r, and on nt or BB wiggles?

  • How does internal CMB delensing compare to external (e.g. CIB)?

Blake says external cleaning won't be good enough for 1 uK noise levels.


  • What sensitivity and resolution do we need for the lensing map?