Hi, most accepted Dark Energy theory is not based on material/dark particles pushing objects away from each other, you may mix it with Dark Matter theory (explaining "missing" mass of galaxies etc). However, I see that this thread was to explain the issue that universe is larger than light speed would allow, and for this purpose explaining the topic on the currently accepted hypothesis/theories is logical to keep the answers simple. Discussing proving of the dark energy theory and especially doscussiong alternative theories for sure deserve their own thread.