If we imagine that the vacuum all around us is filled up with a Planck-scaled crystalline network of oscillating Axion-Higgs-particles, then the vacuum is MORE DENSE than a Neutron star's Fermion interior.
This is hardly to imagine, but a real possibility to explain all relativity effects .
If we also assume that Higgs particles have a special form which can change by collision into other forms, like electron- positron pairs or Gluons, Photons, and gravitons, then a sort of double LESAGE gravity is showing up. see for single Le Sage gravity: