Difference between revisions of "W and gamma"

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(''Nick writing on behalf of Mat'')
 
(''Nick writing on behalf of Mat'')
  
From the sigma8(z) constraints posted here , we looked into how well we can constrain w and delta gamma, where delta gamma quantifies a departure from the GR growth rate gamma ( see [https://arxiv.org/pdf/1201.2434.pdf Weinberg et al. 2012])
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From the sigma8(z) constraints posted ([[SZ_s8_z |sigma 8 of z constraints link]]), we looked into how well we can constrain w and delta gamma, where delta gamma quantifies a departure from the GR growth rate gamma (see [https://arxiv.org/pdf/1201.2434.pdf Weinberg et al. 2012]).
  
 
[[File:s8resTP.png]]
 
[[File:s8resTP.png]]
  
Temperature plus polarization CMB Halo mass calibration
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Temperature plus polarization CMB Halo mass calibration.
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The error bands are for z-bins of width 0.1
  
 
[[File:s8resP.png]]
 
[[File:s8resP.png]]
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Polarization only CMB Halo mass calibration
 
Polarization only CMB Halo mass calibration
  
If we
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gamma = 0.55 + 0.05(1 + w) and Delta gamma equivalent to 0.05(1 + w) so w = -0.8 corresponds to delta gamma 0.01.
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Note that a lot of the constraint for w (and mnu) is just coming from pinning down sigma8 today. Not so much from knowing its z dependence. Although if there were some motivation for a general w(z) or delta gamma (z), those would be better constrained by this.

Latest revision as of 11:10, 15 March 2017

(Nick writing on behalf of Mat)

From the sigma8(z) constraints posted (sigma 8 of z constraints link), we looked into how well we can constrain w and delta gamma, where delta gamma quantifies a departure from the GR growth rate gamma (see Weinberg et al. 2012).

S8resTP.png

Temperature plus polarization CMB Halo mass calibration. The error bands are for z-bins of width 0.1

S8resP.png

Polarization only CMB Halo mass calibration

gamma = 0.55 + 0.05(1 + w) and Delta gamma equivalent to 0.05(1 + w) so w = -0.8 corresponds to delta gamma 0.01.

Note that a lot of the constraint for w (and mnu) is just coming from pinning down sigma8 today. Not so much from knowing its z dependence. Although if there were some motivation for a general w(z) or delta gamma (z), those would be better constrained by this.