2024 March 23 | William Beordo, Mariateresa Crosta, Mario G. Lattanzi, Paola Re Fiorentin, Alessandro Spagna
The paper investigates the Milky Way rotation curve using Gaia DR3 data, focusing on the role of gravitational dragging and dark matter. The authors select 719,143 young disc stars within |z| < 1 kpc and up to R ≥ 19 kpc, providing a large sample of high-quality astrometric and spectrophotometric data. They fit both a classical velocity profile model with a dark matter halo and a general relativistic (GR) analogue derived from a dust disc-scale metric. The results show that both models explain the observed rotational velocities with similar statistical quality, confirming that the geometrical effect driven by GR can explain the flatness of the Milky Way rotation curve, similar to the contribution of dark matter in the classical model. The GR model, which does not require dark matter, suggests that gravitational dragging can account for ∼30–37% of the velocity profile at the Sun's distance, similar to the halo contribution in the classical model. This supports the idea that Einstein's geometry plays a significant role in the Milky Way's dynamics and calls for further investigation into the origin of gravitational dragging.The paper investigates the Milky Way rotation curve using Gaia DR3 data, focusing on the role of gravitational dragging and dark matter. The authors select 719,143 young disc stars within |z| < 1 kpc and up to R ≥ 19 kpc, providing a large sample of high-quality astrometric and spectrophotometric data. They fit both a classical velocity profile model with a dark matter halo and a general relativistic (GR) analogue derived from a dust disc-scale metric. The results show that both models explain the observed rotational velocities with similar statistical quality, confirming that the geometrical effect driven by GR can explain the flatness of the Milky Way rotation curve, similar to the contribution of dark matter in the classical model. The GR model, which does not require dark matter, suggests that gravitational dragging can account for ∼30–37% of the velocity profile at the Sun's distance, similar to the halo contribution in the classical model. This supports the idea that Einstein's geometry plays a significant role in the Milky Way's dynamics and calls for further investigation into the origin of gravitational dragging.