Gravitational orbits in the expanding Universe revisited

Modified Newtonian equations for gravitational orbits in the expanding Universe indicate that local gravitationally bounded systems like galaxies and planetary are unaffected by expansion of Universe. This result is derived space described standard FLRW metric. In this paper, modified conformal cosmology (CC) metric, comoving proper times different similarly as distances. As shown Vavryčuk (Front. Phys. 2022), metric advantageous, because it properly predicts cosmic time dilation, fits Type Ia supernova luminosity observations with no need to introduce dark energy. Surprisingly, solution based on CC behaves quite differently than contrast common opinion resist expansion, they expand according Hubble flow The evolution exemplified numerical modelling spiral galaxies. size grows consistently a typical pattern well reproduced. theory flat rotation curves without an assumption matter surrounding galaxy. resolves challenges ΛCDM model such problem faint satellite galaxies, baryonic Tully-Fisher relation or radial acceleration relation. Furthermore, puzzles solar system successfully explained Faint young Sun paradox Moon’s Titan’s orbit anomalies.