Our Universe began forming in its location of the origin at the Big Bang event 13.8 billion years ago; - space began, expanded through inflation, accordingly time needed to begin its uniformed succession in the primordial existence of said event. The universe grew from an almost infinitely small point to nearly an octillion times in size called Cosmic inflation - a faster than light expansion of the universe that spawned the primordial existence, following this universe continued to expand at a slower rate. The acceleration of this expansion began after the universe was already over 7.7 to 9.8 billion years old, called metric expansion of the space. The current rate of expansion of the universal space is between 66 and 74 km/s/Mpc (kilometers per second per mega-parsec.)
1. Therefore, there is no centre of the current universe; as it was left at the location of its origin.
2. Gravity does not have influence within the intergalactic space, at least, in intergalactic scale, specifically ruled by some mysterious influence.
3. The distant galaxies observed to be surrounded by zero-gravity spheres within specific intergalactic space.
4. The accelerated expansion of the intergalactic space recede the distant galaxies due to said mysterious influence.
5. The galaxies at the edge of the visible universe observed to be receding faster than the light speed. Those galaxies are entering into invisible universe, so that light cannot reach us from such distance.
6. The space, within the gravitationally bound cluster or super cluster of galaxies, does not expand.
7. Some non-luminous non-interacting material appears to make up most of the mass of galaxies and galaxy clusters.