There is no complete quantum field theory of gravitons due to an outstanding mathematical problem with renormalization in general relativity.
If it exists, the graviton is expected to be massless because the gravitational force has a very long range, and appears to propagate at the speed of light.
[13] These infinite results cannot be removed because quantized general relativity is not perturbatively renormalizable, unlike quantum electrodynamics and models such as the Yang–Mills theory.
Therefore, incalculable answers are found from the perturbation method by which physicists calculate the probability of a particle to emit or absorb gravitons, and the theory loses predictive veracity.
Those problems and the complementary approximation framework are grounds to show that a theory more unified than quantized general relativity is required to describe the behavior near the Planck scale.
In contrast, the Standard Model is not background-independent, with Minkowski space enjoying a special status as the fixed background space-time.
Unambiguous detection of individual gravitons, though not prohibited by any fundamental law, has been thought to be impossible with any physically reasonable detector.
For example, a detector with the mass of Jupiter and 100% efficiency, placed in close orbit around a neutron star, would only be expected to observe one graviton every 10 years, even under the most favorable conditions.
[28] Solar system planetary trajectory measurements by space missions such as Cassini and MESSENGER give a comparable upper bound of 3.16×10−23 eV/c2.
[29] The gravitational wave and planetary ephemeris need not agree: they test different aspects of a potential graviton-based theory.
Attempts to extend the Standard Model or other quantum field theories by adding gravitons run into serious theoretical difficulties at energies close to or above the Planck scale.