This code allows the user to calculate TT, EE, and BB power spectra (as separate scalar [for TT and EE], vector, and tensor contributions) for "wiggly" cosmic strings described by the Unconnected Segment Model from the following paper:
L. Pogosian & T. Vachaspati, Phys. Rev. D60, 083504 (1999) (astro-ph/9903361).
The code interpolates between a suite of precomputed outputs of CMBACT, the public code that accompanies that paper. The properties of the strings are described by four parameters:
- Gmu: dimensionless string tension
- nu: rms transverse velocity (as fraction of c)
- alpha: "wiggliness"
- xi: comoving correlation length of the string network
It is written as a Fortran 90 module, and is described in further detail in the following paper:
"Predicted Constraints on Cosmic String Tension from Planck and Future CMB Polarization Measurements" by S. Foreman, A. Moss, & D. Scott, Phys. Rev. D84, 043522 (2011) (astro-ph/1106.4018).
See the header of the source file for usage instructions.
The tarball contains:
stringfast.f90, the main source file;- 8 data files with suffix
.sfp, which are read into memory by the module at runtime and must remain in the same directory as the executable file; driver.f90, a small driver program illustrating a simple use of the module;- and a Makefile for the driver program.