|Testing General Relativity with LISA Including Spin Precession and Higher Harmonics in the Waveform
|467, 9th LISA Symposium
|I present the updated results of Huwyler et al. (2011), where we study the use of multiple alternative theory parameters to determine the accuracy at which a classic LISA configuration should be able to observe deviations from General Relativity through the inspiral of supermassive black holes in the low frequency approximation.
In order to reach higher accuracy, we include the correlation breaking effects of full spin precession and higher harmonics.
We use an implementation similar to the ppE formalism by Yunes and Pretorius. While many studies performing Monte Carlo simulations with the ppE formalism
consider leading order deviations, we try to take another viewpoint and introduce six simultaneous phase correction parameters
accounting for modified gravity in the second post-Newtonian gravitational wave phase. This approach will not be able to find all currently proposed
types of alternative theories (some will fall through our ‘sieve’), but will enable us to quantify the accuracy lost by introducing
multiple corrections at the same time and to investigate next-to-leading order effects. In our study we performed simulations for binaries
with total masses in the range of 105M☉ < M < 108 M☉ on quasi-circular orbits.
In order to find error distributions for the alternative theory parameters and to investigate correlations, we apply the Fisher information formalism for
103 randomly distributed points in the parameter space each, comparing the full (FWF) and restricted (RWF) version of the gravitational waveform.
As an application, we compute an optimal lower bound on the graviton ‘mass’.