Thus, the Lambda-CDM model, the current standard model of cosmology which uses the FLRW metric, includes the cosmological constant, which is measured to be on the order of 10−52 m−2.
It may be expressed as 10−35 s−2 (by multiplication with c2, i.e. ≈1017 m⋅s−2) or as 10−122 ℓP−2 (where ℓP is the Planck length)..
In modern cosmology it is the leading candidate for dark energy, the cause of the acceleration of the expansion of the universe.
In the context of cosmology the cosmological constant is a homogeneous energy density that causes the expansion of the universe to accelerate..
Figure 1: The cosmological constant was originally introduced by Einstein in 1917 as a repulsive force required to keep the Universe in static equilibrium.
In modern cosmology it is the leading candidate for dark energy, the cause of the acceleration of the expansion of the universe..
Einstein first proposed the cosmological constant (not to be confused with the Hubble Constant) usually symbolized by the greek letter "lambda" (Λ), as a mathematical fix to the theory of general relativity..
The general theory of relativity predicts a time dilatation in a gravitational field, so that, relative to someone outside of the field, clocks (or atomic processes) go slowly.
This retardation is a consequence of the curvature of space-time with which the theory identifies the gravitational field..
Einstein first proposed the cosmological constant (not to be confused with the Hubble Constant) usually symbolized by the greek letter "lambda" (Λ), as a mathematical fix to the theory of general relativity.
In its simplest form, general relativity predicted that the universe must either expand or contract..
Einstein originally introduced the constant in 1917 to counterbalance the effect of gravity and achieve a static universe, a notion that was the accepted view at the time..
History.
Einstein included the cosmological constant as a term in his field equations for general relativity because he was dissatisfied that otherwise his equations did not allow for a static universe: gravity would cause a universe that was initially non-expanding to contract..
In modern cosmology it is the leading candidate for dark energy, the cause of the acceleration of the expansion of the universe.
In the context of cosmology the cosmological constant is a homogeneous energy density that causes the expansion of the universe to accelerate..
In the past direction, neither matter not a lambda can alter its behaviour and avoid a singularity, but in the future, a matter-filled Kasner model looks like Einstein-de Sitter, while a ‘lambda-Kasner’ universe looks like de Sitter.
In addition, the Kasner universe plays a significant role in many parts of cosmology.
These universes are all homogeneous but anisotropic; the Kasner model is described by the simplest one of them, the Bianchi type I, and so could accommodate other features not present in simple isotropic ones, like shear, vorticity, and anisotropic curvature, with respect to an overall isotropic Hubble flow.
It describes an anisotropic universe without matter (i.e., it is a vacuum solution ).
It can be written in any spacetime dimension and has strong connections with the study of gravitational chaos . and contains constants , called the Kasner exponents.
In addition, the Kasner universe plays a significant role in many parts of cosmology.
Its late-time asymptotics (as time approaches infinity) are isotropic, as they approach the Einstein-de Sitter, and so Kasner may be a suitable model for the real universe.
American mathematician
Solution of Einstein field equations
