A Comprehensive Investigation on the Slowing Down of Cosmic Acceleration

Wang, Shuang; Hu, Yazhou; Li, Miao; Li, Nan

doi:10.3847/0004-637x/821/1/60

Cited by 30 publications

(33 citation statements)

References 96 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, some recent work has tried to find a slowing down of the acceleration. Moreover, this novel phenomenon has attracted much attention [48][49][50][51][52][53], including the recent work of [54]. Using the dark energy parameterizations, one found that the cosmic acceleration may already have peaked, and the expansion may be slowing down from the deceleration parameter being q 0 > 0.…”

Section: Convergence Issue In Current Datamentioning

confidence: 99%

What do we know about cosmography

Zhang

Xia

2017

Eur. Phys. J. C

View full text Add to dashboard Cite

In the present paper, we investigate the cosmographic problem using the bias-variance trade-off. We find that both the z-redshift and the y = z/(1 + z)-redshift can present a small bias estimation. It means that the cosmography can describe the supernova data more accurately. Minimizing risk, it suggests that cosmography up to the second order is the best approximation. Forecasting the constraint from future measurements, we find that future supernova and redshift drift can significantly improve the constraint, thus having the potential to solve the cosmographic problem. We also exploit the values of cosmography on the deceleration parameter and equation of state of dark energy w(z). We find that supernova cosmography cannot give stable estimations on them. However, much useful information was obtained, such as that the cosmography favors a complicated dark energy with varying w(z), and the derivative dw/dz < 0 for low redshift. The cosmography is helpful to model the dark energy.

show abstract

Section: Convergence Issue In Current Datamentioning

confidence: 99%

What do we know about cosmography

Zhang

Xia

2017

Eur. Phys. J. C

View full text Add to dashboard Cite

show abstract

“…(6) and (7), we can reconstruct the deceleration parameter via OHD and distance measurements, respectively. In Figure 1 [23]. In common picture, q(z) decreases from positive to negative with the decreasing redshift.…”

Section: Cosmic Kinematicsmentioning

confidence: 55%

“…Although many parameterizations [23] were considered, there still exists some tensions because of the drive of model-dependence. On the one hand, they were busy balancing the tension between different models.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Test of the cosmic evolution using Gaussian processes

Zhang

Xia

2016

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

Much focus was on the possible slowing down of cosmic acceleration under the dark energy parametrization. In the present paper, we investigate this subject using the Gaussian processes (GP), without resorting to a particular template of dark energy. The reconstruction is carried out by abundant data including luminosity distance from Union2, Union2.1 compilation and gamma-ray burst, and dynamical Hubble parameter. It suggests that slowing down of cosmic acceleration cannot be presented within 95% C.L., in considering the influence of spatial curvature and Hubble constant. In order to reveal the reason of tension between our reconstruction and previous parametrization constraint for Union2 data, we compare them and find that slowing down of acceleration in some parametrization is only a "mirage". Although these parameterizations fits well with the observational data, their tension can be revealed by high order derivative of distance D. Instead, GP method is able to faithfully model the cosmic expansion history.

show abstract

“…For examples, the best FA recipe obtained in this work can be used to constrain various DE models [66][67][68][69][70][71][72][73][74]. Besides, it can be used to explore the dynamical evolution of DE EoS by using various model-independent methods [75][76][77][78][79][80][81][82]. In addition, based on the improved FA technique, a series of related topics, such as dark sector interaction [83], massive neutrino [84], cosmic age [85][86][87], cosmic fate [88] and so on, need to be revisited.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Exploring JLA supernova data with improved flux-averaging technique

Wang

Wen

2017

J. Cosmol. Astropart. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. In this work, we explore the cosmological consequences of the "Joint Light-curve Analysis" (JLA) supernova (SN) data by using an improved flux-averaging (FA) technique, in which only the type Ia supernovae (SNe Ia) at high redshift are flux-averaged. Adopting the criterion of figure of Merit (FoM) and considering six dark energy (DE) parameterizations, we search the best FA recipe that gives the tightest DE constraints in the (z cut , ∆z) plane, where z cut and ∆z are redshift cut-off and redshift interval of FA, respectively. Then, based on the best FA recipe obtained, we discuss the impacts of varying z cut and varying ∆z, revisit the evolution of SN color luminosity parameter β, and study the effects of adopting different FA recipe on parameter estimation. We find that: (1) The best FA recipe is (z cut = 0.6, ∆z = 0.06), which is insensitive to a specific DE parameterization. (2) Flux-averaging JLA samples at z cut ≥ 0.4 will yield tighter DE constraints than the case without using FA. (3) Using FA can significantly reduce the redshift-evolution of β. (4) The best FA recipe favors a larger fractional matter density Ω m . In summary, we present an alternative method of dealing with JLA data, which can reduce the systematic uncertainties of SNe Ia and give the tighter DE constraints at the same time. Our method will be useful in the use of SNe Ia data for precision cosmology.

show abstract

A Comprehensive Investigation on the Slowing Down of Cosmic Acceleration

Cited by 30 publications

References 96 publications

What do we know about cosmography

What do we know about cosmography

Test of the cosmic evolution using Gaussian processes

Exploring JLA supernova data with improved flux-averaging technique

Contact Info

Product

Resources

About