Has physicist's gravity theory solved 'impossible' dark energy riddle?

Prof Claudia de Rham's 'massive gravity' theory could explain why universe expansion is accelerating

Cosmologists don't enter their profession to tackle the easy questions, but there is one paradox that has reached staggering proportions.

Since the big bang, the universe has been expanding, but the known laws of physics suggest that the inward tug of gravity should be slowing down this expansion. In reality, though, the universe is ballooning at an accelerating rate.