Dark energy is a hypothetical form of energy that is believed to make up about 70% of the total energy density of the universe. It is thought to be responsible for the acceleration of the expansion of the universe.
Dark energy is thought to have a repulsive effect on the expansion of the universe, causing it to accelerate. This is in contrast to gravity, which has a attractive effect and would normally slow down the expansion.
The main evidence for dark energy comes from observations of the expansion of the universe. Scientists have observed that the expansion is accelerating, and this can only be explained by the presence of a repulsive force, which is thought to be dark energy.
Dark energy is thought to have played a role in the early universe during the expansionary phase, when the universe was rapidly expanding. It is believed that dark energy caused the expansion to accelerate during this time.
No, dark energy and dark matter are two separate concepts. Dark matter is a hypothetical form of matter that is thought to make up about 27% of the total mass-energy density of the universe. It is believed to have a gravitational effect on the expansion of the universe, but it is not thought to be responsible for the acceleration of the expansion like dark energy is.