Is there some type of exception to the singularity for gravitons? And if not gravitons then what? I understand the spacetime curvature except why does a sun not collapse in on itself right now when it does after fusion has stopped? I'm told it's from energy creating pressure outwards counteracting the inward pull of gravity but that would suggest that an interaction between particles is taking place, no? And if the pressure created by fusion pushes more against gravity than the normal matter does after fusion has stopped, should the sun not be expanding?