The acceleration of the universe's expansion, as observed through measurements of distant supernovae, is the primary observational evidence for the existence of dark energy.

The cosmological constant is a constant energy density that permeates space and is thought to be responsible for the acceleration of the universe's expansion.

The equation of state for dark energy is typically parameterized by the parameter w, which is the ratio of the pressure of dark energy to its energy density. For dark energy, w is thought to be approximately equal to -1.

Dark energy is thought to make up about 70% of the total energy density of the universe, with the remaining 30% being attributed to matter (including dark matter).

The main challenge in studying dark energy is that it is difficult to detect directly. This is because dark energy does not interact with matter in the same way that ordinary matter does, making it difficult to measure its properties.

According to the current understanding of dark energy, the universe will continue to expand forever. This is because dark energy is causing the expansion of the universe to accelerate, and there is no known force that can stop this acceleration.

Dark energy and the cosmological constant are the same thing. The cosmological constant is a constant energy density that permeates space, and dark energy is the name given to the unknown physical phenomenon that is causing the acceleration of the universe's expansion.

The main goal of the Dark Energy Survey is to measure the properties of dark energy, such as its equation of state and its energy density.

The Wilkinson Microwave Anisotropy Probe (WMAP) was a satellite that was launched in 2009 to study dark energy by measuring the cosmic microwave background radiation.

The Nancy Grace Roman Space Telescope is an upcoming space telescope that will study dark energy by measuring the expansion of the universe and the distribution of galaxies.

Dark energy is causing the expansion of the universe to accelerate, and there is no known force that can stop this acceleration. Therefore, dark energy will cause the universe to expand forever.

Dark energy is causing the expansion of the universe to accelerate, and this acceleration is causing spacetime to be flat.

Dark energy is causing the expansion of the universe to accelerate, and this acceleration is causing the cosmic microwave background radiation to become less uniform.

Dark energy is causing the expansion of the universe to accelerate, but this acceleration has no effect on the abundance of light elements in the universe.

Dark energy is causing the expansion of the universe to accelerate, but this acceleration has no effect on the formation or evaporation of black holes.