Evidence for the Fifth Element Astrophysical status of Dark Energy

Abstract

Evidence for an accelerated expansion of the universe as it has been revealed ten years ago by the Hubble diagram of distant type Ia supernovae represents one of the major modern revolutions for fundamental physics and cosmology. It is yet unclear whether the explanation of the fact that gravity becomes repulsive on large scales should be found within general relativity or within a new theory of gravitation. However, existing evidences for this acceleration all come from astrophysical observations. Before accepting a drastic revision of fundamental physics, it is interesting to critically examine the present situation of the astrophysical observations and the possible limitation in their interpretation. In this review, the main various observational probes are presented as well as the framework to interpret them with special attention to the complex astrophysics and theoretical hypotheses that may limit actual evidences for the acceleration of the expansion. Even when scrutinized with sceptical eyes, the evidence for an accelerating universe is robust. Investigation of its very origin appears as the most fascinating challenge of modern physics.

50 pages, 7 figures, to appear in Astronomy and Astrophysics Review, minor typo changes and references

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Cited by in corpus (18)

• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• Observational Probes of Cosmic Acceleration
• Constraints on dark energy from H II starburst galaxy apparent magnitude versus redshift data
• Galaxy cluster number count data constraints on cosmological parameters
• Exact nonlinear inhomogeneities in $\Lambda$CDM cosmology
• Cluster counts: calibration issue or new physics?
• The 400d Galaxy Cluster Survey weak lensing programme: II: Weak lensing study of seven clusters with MMT/Megacam
• Time-dependent $G$ in Einstein's equations as an alternative to the cosmological constant
• Observational constraints on scalar field models of dark energy with barotropic equation of state
• Quintessence versus phantom dark energy: the arbitrating power of current and future observations
• On the role of shear in cosmological averaging II: large voids, non-empty voids and a network of different voids
• Can Dark Energy emerge from quantum effects in compact extra dimension ?
• Forecasting cosmological parameter constraints from near-future space-based galaxy surveys
• X-ray galaxy clusters abundance and mass temperature scaling
• Inhomogeneous and anisotropic Universe and apparent acceleration
• Can Dark Energy Emerge from a Varying $G$ and Spacetime Geometry?
• White dwarfs as a probe of dark energy
• Cosmological constraints from supernova data set with corrected redshift