If gravity spreads in vacuum, it is due to cosmic vacuum that is not the empty space of our world. Gravity runs through another universe in our universe.

So atoms’ energy can not reach zero degree kelvin. Residual energy persists. Then Andrei SAKHAROV found that relativistic phenomenon that slows clocks was due to a zero-point field. In other words, there is always a field even if we empty it.

Finally, Jean-Pierre PETIT works on a galaxy model with seven dimensions instead of four. So there are fields that run on our space.