Precessing supermassive black hole binaries and dark energy measurements with LISA

Understand

Spin induced precessional modulations of gravitational wave signals from supermassive black hole binaries can improve the estimation of luminosity distance to the source by space based gravitational wave missions like the Laser Interferometer Space Antenna (LISA).

• We study how this impacts the ablity of LISA to do cosmology, specifically, to measure the dark energy equation of state (EOS) parameter $w$.
• Using the $\Lambda$CDM model of cosmology, we show that observations of precessing binaries by LISA, combined with a redshift measurement, can improve the determination of $w$ up to an order of magnitude with respect to the non precessing case depending on the masses, mass ratio and the redshift.