Dynamical dark energy or simply cosmic curvature?

By C. Clarkson, Marina Cortês, Bruce A. Bassett. 2007

183 citations recorded by the source corpus.

We show that the assumption of a flat universe induces critically large errors in reconstructing the dark energy equation of state at even if the true cosmic curvature is very small, or less. The spuriously reconstructed w(z) shows a range of unusual behaviour, including crossing of the phantom divide and mimicking of standard tracking quintessence models. For 1% curvature and ΛCDM, the error in w grows rapidly above z∼0.9 reaching (50%,100%) by redshifts of (2.5,2.9) respectively, due to the long cosmological lever arm. Interestingly, the w(z) reconstructed from distance data and Hubble rate measurements have opposite trends due to the asymmetric influence of the curved geodesics. These results show that including curvature as a free parameter is imperative in any future analyses attempting to pin down the dynamics of dark energy, especially at moderate or high redshifts.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/acc09e85c84a1854598f1551d40f1e50723f6b5d

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. Hai-Bo Yu
2. Fa-yin Wang
3. P. Bull
4. Pedro G. Ferreira
5. P. Patel
6. Mário G. Santos
7. Bharat Ratra
8. Tiberiu Harko

In Instrumentation

1. Mário G. Santos
2. Bharat Ratra
3. Pedro G. Ferreira
4. Fa-yin Wang
5. Hai-Bo Yu

Citations in the corpus

• LATE-TIME COSMOLOGY WITH 21 cm INTENSITY MAPPING EXPERIMENTS (2014, background): “Indeed, a percent level uncertainty in ΩK can lead to a ~100% error on the recovery of more exotic forms for w(z) (Clarkson et al. 2007), although it has been argued that current constraints can already mitigate this (Okouma et al. 2013).”
• Hubble Parameter and Baryon Acoustic Oscillation Measurement Constraints on the Hubble Constant, the Deviation from the Spatially Flat ΛCDM Model, the Deceleration–Acceleration Transition Redshift, and Spatial Curvature (2017, methodology): “…of redshift, may be used in conjunction with BAO observations, which give a distance as a function of redshift, to measure spatial curvature (Clarkson et al. 2007, 2008; Mörtsell & Jönsson 2011; Li et al. 2014; Sapone et al. 2014; Takada & Doré 2015; Cai et al. 2016; Li et al. 2016; Yu &…”
• f(R) Theories Of Gravity (2008, unknown): “In any case, results derived under the assumption that k = 0 should be considered preliminary until the influence of the spatial curvature is precisely determined, since there are indications that even a very small value of Ωk may have an effect on them [see, for instance (Clarkson et al., 2007)].”