how to set omegam and H0 range to use parameterization = background

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
Post Reply
Liang Yu Astro
Posts: 5
Joined: November 15 2012
Affiliation: cosmo

how to set omegam and H0 range to use parameterization = bac

Post by Liang Yu Astro » June 02 2013

Hi,

I'm new in this filed, and want to use
SN or BAO data alone or SN&BAO or SN&HST or SN&BAO&HST
to run cosmomc to get something like
http://supernova.lbl.gov/Union/figures/ ... _slide.pdf
so setting parameterization = background is necessary.

But how to set the parameter properly?
I add
param[omegam] = 0.275 0.1 0.4 0.001 0.001
param[H0] = 60 20 100 0.1 0.1
and use other parameter as defult.
But cosmomc abort with:
MCMC.f90: Couldn't start after 1000 tries - check starting ranges.

How can I fix it?

Thanks a lot in advance!

Antony Lewis
Posts: 1644
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

Re: how to set omegam and H0 range to use parameterization =

Post by Antony Lewis » June 03 2013

I've run with relevant settings like this:

Code: Select all

parameterization = background
use_CMB=F
use_clik=F
sampling_method = 1
use_fast_slow = F
get_sigma8=F
num_massive_neutrinos=1
param[mnu] = 0.06 0.06 0.06 0 0
param[omegak] = 0 -1.5 1.5 0.05 0.05
param[omegam] = 0.3 0 4 0.1 0.1
param[H0] = 70 40 100 5 5
Of course your likelihood has to not reject prosed points.

Post Reply