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Muhammad Junaid
Joined: 05 Jan 2017 Posts: 7 Affiliation: University of Alberta

Posted: January 06 2017 


I have been using your 'Camb' code to calculate transfer functions for my research. I am interested in calculation of T_{SW}(k) and T_{D}(k) where these are SachsWolfe and Doppler terms as given in Eq. (7.3.58) DAMPT lectures on cosmology (http://www.damtp.cam.ac.uk/user/db275/Cosmology2015.pdf) so can you help me with that.
I also wanted to know the units of Camb code output velocity transfer functions vel / k^{2} and if one multiplies vel / k^{2} by k^{2} then what will be the units of vel Transfer functions 11, 12 13. 

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Antony Lewis
Joined: 23 Sep 2004 Posts: 1249 Affiliation: University of Sussex

Posted: January 06 2017 


You can get individual terms for the sources by commenting appropriately the terms in output() in equations.f90. Doppler and ISW terms are already there (commented or not).
The transfer functions should be dimensionless (and normalized for unit initial superhorizon curvature perturbation). 

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Muhammad Junaid
Joined: 05 Jan 2017 Posts: 7 Affiliation: University of Alberta

Posted: January 06 2017 


So how can i access to value of Doppler term, as I have uncommented the code in output() but i don't see any new result in transfer_function output file. How can I output the doppler term in the transfer function output file.
Secondly, is there any way one can calculate the transfer function without the comoving perturbations part as in Eq. 7.3.58 of Dampt lectures, , as I just need T_{D} and T_{SW}. You see, I calculate the power spectrum for the comoving perturbations using my own model (code) and I only need the T_{SW} and T_{D} part of the transfer functions. 

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