A minimal fractional deformation of Newtonian gravity

Abstract: We consider a minimal fractional deformation of Newtonian gravity characterized by a single parameter $α$. In the limit $α\to 1$, the theory reduces to standard Newtonian gravity. Previous works showed that the $Λ$CDM cosmology consistently emerges from this framework. Using a single potential, the model reproduces the full sequence of cosmic evolution (from a nonsingular pre--inflationary phase and a stable inflationary attractor to the radiation- and matter-dominated eras and the present accelerated expansion) and accounts for the growth of large-scale structure for $|α-1|\ll1$, in agreement with current observations. Here we show that the same fractional Newtonian model also describes key weak--field tests, including the perihelion precession of Mercury and the gravitational deflection of light, using a unified potential with the same constraint on $α$. These results suggest that the minimal fractional Newtonian framework may provide a unified phenomenological description of gravitational dynamics from Solar-System scales to cosmology. Finally, this fractional cosmological framework may offer new perspectives on problems such as the cosmological constant, the hierarchy of cosmological scales, and the Hubble tension.