Originally Posted by absael

The fact that a particle hasn't yet been detected doesn't mean that we can ascribe any properties to it that we wish... theory dictates that the antiparticles of chargeless bosons such as the graviton, photon and Z boson are identical to the particles (you could also take this to mean that the antiparticle doesn't exist). If you believe that the theory is incorrect, you should provide some proof, or at least your reasoning for believing so, other than that the existence of particles with those properties would cause accelerating expansion. I saw nothing in any of your posts that explains why the physicists who postulated the existence of the graviton were mistaken in their description of its antiparticle.