Additional contributions to the phase and frequency of the chirp

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In recent years additional relativistic corrections to the binary inspiral chirp formula have been calculated. These have now been included in GRASP, and are available to users generating template banks. The changes have been implemented in existing GRASP routines, and using them requires minimal modification of your code. Furthermore, if you have written GRASP code that uses only second post Newtonian chirps - and you want to keep it that way - you don't need to do anything: all the modifications are compatible with previous GRASP releases.

When the original code for the GRASP chirp generator was written, only the second post-Newtonian relativistic corrections to the phase and frequency evolution were available. These are depicted in Eqs. () and (), and implemented in the phase_frequency() routine. The routine used for generating template banks, make_filters(), uses these formulae by calling phase_frequency(). In the next two subsubsections we discuss extensions of these formulae and routines to include the contributions to the phase and frequency produced by the spins of the objects (spin-orbit coupling, and spin-spin coupling) and also the contribution from the 2.5 post-Newtonian order corrections. In future GRASP releases we hope to include contributions to the phase and frequency produced by the quadrupole moment of the bodies and higher-order post-Newtonian effects.