What you more likely mean is the "absolute" total of both positive and negative energies in the form of light/matter versus gravity respectively. Reminiscent of absolute convergence from mathematics [1]
Amount of gravitational energy is proportional to light/matter, so in theory, we should only need to solve for one thing - the amount of light/matter or the amount of gravity. Since gravity is non-renormalizable (mass -> gravity -> mass -> ........ -> gravity), it's not clear whether gravity or light/matter is more fundamental. They are clearly coupled but one doesn't necessarily cause the other.
Note that the zero-energy universe is highly speculative; in particular there is no good way to define the total energy confined to a volume at large scales and it's hard to say that "energy is conserved" in any way that's nontrivial. (A ready example is the apparent loss of energy in the redshifting of light due to Hubble expansion.)
What you more likely mean is the "absolute" total of both positive and negative energies in the form of light/matter versus gravity respectively. Reminiscent of absolute convergence from mathematics [1]
Amount of gravitational energy is proportional to light/matter, so in theory, we should only need to solve for one thing - the amount of light/matter or the amount of gravity. Since gravity is non-renormalizable (mass -> gravity -> mass -> ........ -> gravity), it's not clear whether gravity or light/matter is more fundamental. They are clearly coupled but one doesn't necessarily cause the other.
Yeah, paradoxical, I know.
[1] https://en.wikipedia.org/wiki/Absolute_convergence