In QED, the field strength dependence is expressed by a field of virtual photons of varying spatial density. I know that we describe gravity as a warp in space-time, but how can one warp space (and time) if there isn't anything there to warp (how does one warp a vacuum)? We have established the lack of an ether, but the Einstein tensors describe a topological warping that could be expressed as a change in density of a field. Is there any current theory involving a field of virtual gravitons to quantify the field strength?
The real question is "is gravity quantized" ?
In a quantum field theory of gravity there will be a similar construct as the photon field, virtual photons exchanged in interactions, virtual gravitons exchanged in interactions.
String theory quantises gravity and thus has a graviton and virtual gravitons on par with photons and virtual photons. It is still though a theory in progress, no definite model yet.
As for the warping this quote from the link might help if you are mathematically inclined: