*Back To Singularity, Again With A Bang!!*
The expansion of the universe is an intrinsic expansion whereby the scale of space is reducing, so the distance between two distant parts of the universe seems to increase with time.
Specifically, when the scale of the universe halves, space apparently looks doubled in size to us, because the number of markings on the length of the standard ruler remain the same, though, as compared to the previous stage, the ruler has halved in size.
By this intrinsic doubling of space, we now measure, and find that the
"density of matter got reduced by a factor of 8, instead of 2."
Where did the extra 6 factors of matter go?
I speculate that, since we know that the density of dark energy is increasing with the present intrinsic space expansion, we should suspect that, dark energy consumes the extra density lost by matter.
This means that the universe is acceleratingly expanding intrinsically, at a very rapid exponential rate with time. Coming closer and closer to a de Sitter spacetime. If so, it seems we are soon going to enter another phase of inflation.
This time the inflation will not lead us to the EMERGENCE of a new universe, but will lead us to a singularity.
The acceleration caused by dark energy will eventually become so strong that it will completely overwhelm the effects of the gravitational, electromagnetic and strong binding forces.
Thus the immense increase in the density of dark energy with time will cause a steady increase in the Hubble constant.
All normal matter states (even black holes won't get time to degenerate via Hawking radiation) will get disjointed into elementary particles and radiation, and rip apart, and shoot apart from each other.
This would be followed by a
spontaneous entropy decrease by the Poincaré recurrence theorem, thermal fluctuations, and the fluctuation theorem.
The end state of the universe then is a singularity, with the dark energy density becoming infinite. Intrinsic expansion too becoming infinite leading us to the same zero point space Singularity, because space scale become zero.
The infinite force of bounce or roll back is representative of the united fundamental forces. Dark energy will be a separate component.
Dark matter will be a foam of probably zero mass particles, forming the cortex of the singularity, and will gain mass when the super Higgs field forms, as described some posts back.