CosmoMC : comparison with wmap7 results (using WMAP likelihood v4.1)

Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
Post Reply
Sourav Mitra
Posts: 1
Joined: August 10 2010
Affiliation: HRI

CosmoMC : comparison with wmap7 results (using WMAP likeliho

Post by Sourav Mitra » January 27 2011

Dear all,
I am quite new to CosmoMC. I am trying to compare the CosmoMC (May 2010 with WMAP likelihood v4.1) results with WMAP7 derived parameters (Larson et. al 2010) by varying the parameters - { [tex]\Omega_bh^2[/tex], [tex]\Omega_{dm}h^2[/tex], [tex]\theta[/tex], [tex]\tau[/tex], [tex]n_s[/tex], [tex]log[10^{10} A_s][/tex], [tex]a_{sz}[/tex] }. I have used the following -

Computing tensors: F
Doing CMB lensing: T
lmax = 2100
Number of [tex]C_l[/tex] s = 3
Varying 7 parameters ( 0 fast)

My result matches with the WMAP7 results ( using WMAP likelihood v4.1 ) quite accurately, except I got 1-[tex]\sigma[/tex] limit of [tex]\tau[/tex] ~ 0.007, which is lower than WMAP7 value (0.015). Why am I getting such lower value of 1-[tex]\sigma[/tex] limit for [tex]\tau[/tex]? Did I make any mistakes? or Using [tex]H_0[/tex] rather than [tex]\theta[/tex] can solve this confusion? Any help is appreciated.

Thanks in advance.
Sourav.

Post Reply