A purely acceleration-based measurement of the fundamental Galactic parameters (2012.02169v3)

Abstract: Klioner et al. have used the Gaia EDR3 data to directly measure the solar system's acceleration within the Milky Way using the apparent proper motions of quasars. Here I show that this single absolute acceleration measurement in combination with relative accelerations obtained from pulsar orbital decay allows one to determine all of the parameters describing the dynamics of our local Galactic environment, including the circular velocity at the Sun $V_0 = 244 \pm 8$ km/s and its derivative $V'_0 = 2 \pm 9$ km/s/kpc, the local angular frequency, the Oort constants, and the Sun's motion with respect to the LSR. This is the first determination of these parameters that only uses the general theory of relativity without the need for additional assumptions.