Measurement of the Land\'e g-factor ratio of Rb-87 and Rb-85

We report on a measurement of the ratio of the Rb-87 and Rb-85 Land\'e g-factors, $g_F(87)/g_F(85)$, based on the data from the experiment of Jackson Kimball et al., Phys. Rev. D {\textbf{96}}, 075004 (2017). The experiment simultaneously measured the spin-precession frequencies of overlapping ensembles of Rb-87 and Rb-85 atoms contained within an evacuated, antirelaxation-coated vapor cell. The accuracy of this measurement of $g_F(87)/g_F(85)$ exceeds that of previous measurements by over an order-of-magnitude.