The observed acceleration of the universe's expansion

The presence of dark matter in galaxies

The cosmic microwave background radiation

The abundance of heavy elements in the universe

A constant energy density that permeates the entire universe

A measure of the curvature of spacetime

A force that drives the acceleration of the universe's expansion

A property of dark matter

Dark energy drives the acceleration of the universe's expansion

Dark energy slows down the expansion of the universe

Dark energy has no effect on the expansion of the universe

Dark energy causes the universe to contract

The universe will expand forever

The universe will eventually stop expanding and collapse

The universe will reach a steady state

The universe will undergo a Big Rip

$\Lambda = 2.88 \times 10^{-122} m^{-2}$

$\Lambda = 1.1 \times 10^{-35} s^{-2}$

$\Lambda = 6.9 \times 10^{10} yr^{-2}$

$\Lambda = 0.7 \times 10^{-26} kg m^{-3}$

Dark energy is the physical manifestation of the cosmological constant

Dark energy is a different phenomenon from the cosmological constant

Dark energy is a type of dark matter

Dark energy is a property of spacetime

A scalar field known as the quintessence field

A modification of general relativity called MOND

A multiverse scenario

A fifth dimension

Its direct observation is extremely difficult

It is not affected by gravity

It is only present in distant galaxies

It is a purely theoretical concept

Observing distant supernovae to measure the expansion history of the universe

Studying the cosmic microwave background radiation

Searching for new particles that could be related to dark energy

Developing new theoretical models to explain dark energy

It inhibits the formation of new galaxies

It accelerates the formation of new galaxies

It has no effect on the formation and evolution of galaxies

It causes galaxies to merge together

Dark energy is responsible for the observed fluctuations in the cosmic microwave background radiation

Dark energy is unrelated to the cosmic microwave background radiation

Dark energy is responsible for the overall temperature of the cosmic microwave background radiation

Dark energy causes the cosmic microwave background radiation to be polarized

It will cause the universe to expand forever

It will cause the universe to eventually stop expanding and collapse

It will cause the universe to reach a steady state

It will cause the universe to undergo a Big Rip

Dark energy causes spacetime to be curved

Dark energy is a consequence of the curvature of spacetime

Dark energy is unrelated to the curvature of spacetime

Dark energy is a property of spacetime

It causes galaxies to move away from each other at an accelerating rate

It causes galaxies to move towards each other at an accelerating rate

It has no effect on the motion of galaxies

It causes galaxies to rotate faster

Dark energy will determine whether the universe will expand forever or eventually collapse

Dark energy has no effect on the fate of the universe

Dark energy will cause the universe to reach a steady state

Dark energy will cause the universe to undergo a Big Rip