A Mathematica Interface for CAMB (Version 1.1):
We present a Mathematica interface for CAMB (based on September 2006 version).
It allows the user to specify any two-parameter ansatz for the Dark Energy equation of state
w(a) and calculates the TT, TE and EE CMB power spectra in real time.
This means that in order to use another w(a) ansatz there is no need to recompile
any code! Just change w(a) and hit Enter!
The requirements for using the code is only Mathematica v5.2+.
In this demo, which was created in just in a few seconds, the user sees how the CMB power
spectrum scales with H0 for a LCDM cosmology!
… and this happens without having first to calculate the spectra, then import the
data to some other program etc, therefore making the Interface very suitable for
educational purposes as well.
(Note that the
interface is under continuous improvement, so expect that much more
features will be included. See the To-Do part of the project for details.)
(Note that the interface is under continuous improvement, so expect that much more features will be included. See the
To-Do part of the project for details.)
To initiate the interface follow these simple steps:
1) Download the files for your system (Windows or Linux) from the link above.
2) Place them in a directory.
3) Unzip and open with Mathematica (v5.2+) the “camb_interface.nb” file.
Note: Mathematica 6 users should choose the “Do not scan this notebook” option
when they first open the notebook.
4) Change the SetDirectory command to where you placed the files.
5) Evaluate the cells and the interface should run.
Your first calculation:
1) Just hit the “Run CAMB” button! In a few seconds the TT, TE and EE spectra will be shown in the panel below. This model corresponds to LCDM (w0=-1, w1=0)
2) Next, try changing some the parameters or the w(a) ansatz and see what happens!
3) By pressing Ctrl+T a new Tab appears (as in Firefox). The parameters in this tab correspond to that model only. To kill (close) a tab use the kill tab button (write the number of the model you want to delete in the field next to the button and then press it (note that this will change in future versions)).
The Features of the Interface:
Default: w(a)=w0+w1(1-a), w0=-1, w1=0
Default: The values shown in Figure 1
colors in his system by going to the “Plot->More colors” menu (or just press Ctrl+B)
1) Add several more features in the interface (cosmological parameters etc)
2) The choice to give any potential V(phi) (Quintessence) besides w(a)
and calculate the power spectra in real time! (coming very soon!)
In this version (1.1) several features were added (keybord shortcuts, Tabs for the plots and models) and
the incompatibility issue with Mathematica 6 was solved.
Also, a bug (pointed out by S. L. Cherkas) that existed in the previous version was corrected.
1) The only limitation to the range of the w(a) that may be used is that the Dark Energy
density may be calculated in a closed form
that can be understood by fortran, ie in terms of elementary functions like Exp, Sin etc.
In the case that the previous requirement is not met, then CAMB will obviously crash and the Interface will
issue a warning.
2) The performance of the code depends on the computer and model used.
3) Remember that the interface is under constant development so check back the web-page often!
For Questions/Bug reports don’t hesitate to e-mail me.