The Hypothesis is that the Graviton could be the force carrier for gravity. But with the knowledge of Einsteins theory of relativity which states that Gravity is NOT a Force, wouldn’t the Graviton disprove Relativity or at least some aspects of it?
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Force isn’t a good concept to use in modern time, at a technical level. You can use “force” colloquially to give names to something (e.g. force carrier), but it’s not a technical concept to quibble over on whether something is really a force or not.
When Einstein came up with General Relativity, the idea of gravity is not a force was based on Newtonian physics’d real force vs fictitious force. In Newtonian physics, A real force is a force that can be seen in the inertia frame, while a fictitious force is an (otherwise unexplained) acceleration of all objects in a frame accelerating compared to the inertia frame. If you change your reference frame so to “undo” that acceleration, you will eliminate the fictitious force.
Because gravity acts on everything the same way, Einstein posits that it should be like a fictitious force.
However, there is a crucial difference here. Unlike Newtonian physics, you can’t never eliminate gravity altogether just by changing the frame of reference. This is because of the curvature. You can eliminate gravity *locally* up to 1st order only by changing the frame of reference, but if you choose a frame of reference to eliminate gravity at one point, you will see even more gravity elsewhere. Thus, to describe gravity, Einstein needs a metric field, which basically describe which change of frame of reference needed to eliminate gravity at each point. The metric field, of course, can be perceived differently depends on the frame of reference (for example if you’re already at a frame of reference where gravity don’t exist at that point, then the metric you see would be the boring Minkowski metric), but the curvature cannot be eliminated.
From modern perspective, the “true” gravity force is the curvature itself. The metric field is not the source of gravity. (just to put in context, Einstein himself was struggling with philosophical issue regarding space with different metric but indistinguishable gravitational effect – this is the “hole argument”; from modern perspective, this is a meaningless distinction, the 2 spaces are the same, just described differently)
But this is extremely similar to the way other forces are already work in quantum physics. The fermions are described by fields, which does not have exact numerical values; rather, their “perceived” value depends on the frame of reference. The force carriers describes which frame of reference you need to change to to not see that force. Once again, you can eliminate the force at any points by choosing a new frame of reference, but you cannot eliminate it entirely. The curvature of the field is the real source of the force.
Of course, there is still the crucial different between gravity and other forces. Gravity acts the same on all kind of particles, while other forces having different effects. But here is where all sorts of hypothetical come in. For example, for many possible choice of frame of reference, gravity acts differently in different direction; but we only know that because we know how to change the frame of reference. Who is to say that it doesn’t happen for particles too? Perhaps all fermions are really the same thing, we just naturally see them as different because we look at them the wrong way, and once we pick the right frame of reference, other forces act the same on all particles. Perhaps all forces are part of the same whole, and the part that we see as gravity is just the part that act the same on everything.
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