Ranku said:Would not the energy density be completely dominant in the future even if it were to be very slowly decreasing?
The critical question is whether it ends up decreasing faster than [itex]1/a^2[/itex] or not.Drakkith said:I think that may depend on how quickly is decreases. If it decreases slower than the density of normal and dark matter, the outcome is likely to be the same as if it wasn't decreasing at all. But I confess I am not up to speed on all the details, so I could be incorrect.
Will it continue accelerating, even if expanding more slowly?Chalnoth said:But as long as the dark energy density decreases more slowly than [itex]1/a^2[/itex], it will always dominate over the curvature and the universe will expand forever. It will expand more slowly, and the horizon will be much larger. But it will keep expanding.
Yes, as long as the energy density reduces more slowly than this, objects within the universe will continue to accelerate away from one another.Ranku said:Will it continue accelerating, even if expanding more slowly?
Dark energy is a hypothetical form of energy that is believed to make up around 70% of the universe. Its density decreases because it is thought to be spread out evenly throughout space and as the universe expands, the volume of space increases, leading to a decrease in density.
Scientists use various methods to measure the expansion rate of the universe, such as observing the brightness of distant supernovae and the distribution of galaxies. These measurements have shown that the expansion of the universe is accelerating, indicating that the density of dark energy is decreasing.
The decrease in dark energy density has a significant impact on the fate of the universe. It is believed that as the density decreases, the expansion of the universe will continue to accelerate, eventually leading to a "Big Rip" scenario where the universe will expand at an exponential rate and tear apart all matter.
There is currently no evidence to suggest that the density of dark energy will increase again. The current understanding is that it will continue to decrease as the universe expands. However, as our understanding of dark energy is still limited, it is possible that new discoveries could change this in the future.
The decrease in dark energy density has a significant impact on the formation of galaxies and other structures in the universe. As dark energy is the driving force behind the expansion of the universe, its decrease could potentially slow down the formation of new structures in the universe. This could ultimately lead to a "lonely universe" scenario where galaxies become more and more isolated from each other.