The universe was not going to recollapse in the first place.

That means it will one day recollapse, back into a singularity.

This would eventually stop expansion in some regions and cause them to start to recollapse.

Would the Universe recollapse, like the yellow line shows?

So forming galaxies collide with each other as clusters start to recollapse.

Everyone knew, they said loftily, that the universe was never going to recollapse, but would simply go on expanding forever.

In addition, here we have a small sinusoidal modulation of the expansion and recollapse.

Finally, there is a third kind of solution, in which the universe is expanding only just fast enough to avoid recollapse.

As clusters recollapse, the system of galaxies undergoes a violent collective relaxation.

If the density is greater than the critical value, gravity will stop the expansion at some time in the future and cause the universe to recollapse.

Will the expansion continue forever? Or is the universe destined to recollapse, ending in a fiery big crunch?

Gravity would at most slow down the expansion and cause a recollapse hundreds of billions of years in the future, if at all.

Even if the whole universe did not recollapse, there would be singularities in any localized regions that collapsed to form black holes.

In any event the high matter densities before recollapse should disrupt the vacuum state, allowing us to regain control over the drive."

"The universe could still recollapse."

There is no apparent danger of recollapse evident in any of the data for the end of the metasimulation period.

A flat geometry universe, if dominated by regular matter will expand more and more slowly, but never quite stop expanding and recollapse.

The net gravitational effect over many periods is to produce an expansion and recollapse cycle of our family of inertial nonspining observers.

That was what the messages from space had described, years before: the Big Bang and the universe's expansion, the recollapse into the Big Crunch.

The observers periodically expand and recollapse transversely to the direct of propagation; this motion is modulated by short period small amplitude perturbations.

Observationally, the Universe appears to be flat (k = 0), with an overall density that is very close to the critical value between recollapse and eternal expansion.

If the cosmological constant were actually zero, the critical density would also be the dividing line between eventual recollapse of the universe to a Big Crunch, or unlimited expansion.

One can imagine universes governed by general relativity that burst briefly into big bang being, then recollapse in a rapid big crunch within parts of a second or a century.

The initial rate of expansion also would have had to be chosen very precisely for the rate of expansion still to be so close to the critical rate needed to avoid recollapse.

This expansion and recollapse cycle is reminiscent of the expanding and recollapsing FRW cosmological models, and it occurs for a similar reason: the presence of nongravitational mass-energy.