Quantum cosmology is the attempt in theoretical
physics to develop a quantum theory of the
Universe.
This approach attempts to answer open questions
of classical physical cosmology, particularly
those related to the first phases of the universe.
The classical cosmology is based on Albert
Einstein's general theory of relativity (GTR
or simply GR).
It describes the evolution of the universe
very well, as long as you do not approach
the Big Bang.
It is the gravitational singularity and the
Planck time where relativity theory fails
to provide what must be demanded of a final
theory of space and time.
Therefore, a theory is needed that integrates
relativity theory and quantum theory.
Such an approach is attempted for instance
with the loop quantum gravity, the string
theory and the causal set theory.
== See also ==
Dark energy
Minisuperspace
Hamilton–Jacobi–Einstein equation
Theory of everything
