# Dark Energy from structure: a status report

@article{Buchert2007DarkEF, title={Dark Energy from structure: a status report}, author={Thomas Buchert}, journal={General Relativity and Gravitation}, year={2007}, volume={40}, pages={467-527} }

The effective evolution of an inhomogeneous universe model in any theory of gravitation may be described in terms of spatially averaged variables. In Einstein’s theory, restricting attention to scalar variables, this evolution can be modeled by solutions of a set of Friedmann equations for an effective volume scale factor, with matter and backreaction source terms. The latter can be represented by an effective scalar field (“morphon field”) modeling Dark Energy. The present work provides an…

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## References

SHOWING 1-10 OF 287 REFERENCES

Backreaction Issues in Relativistic Cosmology and the Dark Energy Debate

- Physics
- 2006

The effective evolution of an inhomogeneous universe model in Einstein’s theory of gravitation may be described in terms of spatially averaged scalar variables. This evolution can be modeled by…

A cosmic equation of state for the inhomogeneous universe: can a global far-from-equilibrium state explain dark energy?

- Physics
- 2005

A system of effective Einstein equations for spatially averaged scalar variables of inhomogeneous cosmological models can be solved by providing a ‘cosmic equation of state’. Recent efforts to…

Dynamics of dark energy

- Physics
- 2006

We review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating universe. In particular we discuss the arguments for and recent…

Correspondence between kinematical backreaction and scalar field cosmologies—the ‘morphon field’

- Physics
- 2006

Spatially averaged inhomogeneous cosmologies in classical general relativity can be written in the form of effective Friedmann equations with sources that include backreaction terms. In this paper,…

Back reaction of inhomogeneities on the expansion: The evolution of cosmological parameters

- Physics
- 2000

Averaging and evolving inhomogeneities are non-commuting operations. This implies the existence of deviations of an averaged model from the standard Friedmann-Lemaitre cosmologies. We quantify these…

Inhomogeneous alternative to dark energy

- Physics
- 2006

Recently, there have been suggestions that the apparent accelerated expansion of the universe is not caused by repulsive gravitation due to dark energy, but is rather a result of inhomogeneities in…

On cosmic acceleration without dark energy

- Physics
- 2006

We elaborate on the proposal that the observed acceleration of the Universe is the result of the backreaction of cosmological perturbations, rather than the effect of a negative-pressure dark-energy…

The Cosmological Constant and Dark Energy

- Physics
- 2003

Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda: nowadays the concept is termed dark energy or…

On globally static and stationary cosmologies with or without a cosmological constant and the dark energy problem

- Physics
- 2006

In the framework of spatially averaged inhomogeneous cosmologies in classical general relativity, effective Einstein equations govern the regional and the global dynamics of averaged scalar variables…

Extended theories of gravity and their cosmological and astrophysical applications

- Physics
- 2007

Astrophysical observations are pointing out huge amounts of “dark matter” and “dark energy” needed to explain the observed large scale structure and cosmic dynamics. The emerging picture is a…