Does the growth of structure affect our dynamical models of the Universe? The averaging, backreaction, and fitting problems in cosmology

By C. Clarkson, G. Ellis, J. Larena, Obinna Umeh. 2011

210 citations recorded by the source corpus.

Structure occurs over a vast range of scales in the Universe. Our large-scale cosmological models are coarse-grained representations of what exists, which have much less structure than there really is. An important problem for cosmology is determining the influence the small-scale structure in the Universe has on its large-scale dynamics and observations. Is there a significant, general relativistic, backreaction effect from averaging over structure? One issue is whether the process of smoothing over structure can contribute to an acceleration term and so alter the apparent value of the cosmological constant. If this is not the case, are there other aspects of concordance cosmology that are affected by backreaction effects? Despite much progress, this ‘averaging problem’ is still unanswered, but it cannot be ignored in an era of precision cosmology, for instance it may affect aspects of baryon acoustic oscillation observations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/db5039433b58c6aa86faf08e8e9deeace844f0fc

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. E. Puchwein
2. Marco Baldi
3. R. Durrer
4. Martin Kunz
5. Volker Springel
6. J. Adamek
7. David Daverio
8. Joop Schaye

In Nuclear and High Energy Physics

1. E. Puchwein
2. R. Durrer
3. Marco Baldi
4. Martin Kunz
5. David Daverio
6. J. Adamek
7. Volker Springel
8. L. Hernquist

Citations in the corpus

• Modified Gravity-GADGET: A new code for cosmological hydrodynamical simulations of modified gravity models (2013, background): “…effect of the formation of nonlinear cosmic structures on the background expansion of the universe (see e.g. Kolb et al. 2006; Rasanen 2011; Clarkson et al. 2011) or through the presence of a very large void surrounding the Milky Way’s location and mimicking a late-time accelerated…”
• gevolution: a cosmological N-body code based on General Relativity (2016, background): “This is one aspect of the well known “backreaction” problem (see [22, 23] for recent reviews and [24] for a discussion in the present framework).”