CAMB_source: Weak lensing convergence power spectra

[Antony Lewis]

I've made no great effort to make CAMB sources conserve memory since it's not tested for iterated use (e.g. in cosmomc).

I think the lensing results are OK. The ISW-redshift distortion correlation only comes into the counts-CMB cross-correlation. (and of course I think CAMB sources is correct anyway!)


I think at some blissful point in the past, with intel compilers, deallocate(A,stat=err) would set the error flag if A was not allocated rather than crashing. Unfortunately this seems to have changed around version 10.0, and presumably also problems in other compilers, which neccessitates lots of tedious nullify statements, or consistently tracking what is allocated. However in this particular case I don't get the bus error with the intel compiler. The fix is probably to add

Code: Select all

               call MatterPowerdata_Nullify(CAMB_Pk)

at the top of MakeNonLinearSources in cmbmain.f90 - does that help?

[Lukas Hollenstein]

Yes that helped :) Thanks a lot!

Cheers,
Lukas

[gongbo zhao]

Dear all,

For default CAMB source, you can kill the 'bus error' by compiling without '-Openmp' with ifort.


Best,
Gongbo

[Sanaz Vafaei]

Hi,
I was wondering if the above issues are fixed in the 2010 version. Also in the readme it says: ""Note that lensing spectra are also multiplied by CMB_outputscale, so you may want to divide this out of the answer to get a sensible dimensionless spectrum.""
I am also interested in the convergence power spectrum, but I don't understand what exactly am I supposed to divide the C^\ell_\phi by as the readme suggests? Could you please clarify this.
thanks,
Sanaz

[Antony Lewis]

The value of CMB_outputscale in the input .ini file.

However as of Jan 2010 (and forthcoming update) CAMB's lens_potential_output_file output file contains sensibly normalized results for the lensing potential power spectra that don't need re-scaling.

[Sanaz Vafaei]

Thanks Anthony.
Also could you please tell me where I can change the source redshift. I want to got the convergence power spectrum C_\ell^\kappa from the lensing potential C^\phi_\ell. But can not figure out where to choose the source redshift to get the correct corresponding C^\phi_\ell.
Also can I get the matter power spectrum at any redshift I want?
thanks again,
Sanaz

[Antony Lewis]

CAMB only calculates the CMB lensing potential. In "CAMB sources" you can specify Gaussian windows for any distribution, or edit the window function in the code.