The observational data on the anisotropy of the cosmic microwave background constraints the scalar spectral tilt n s and the tensor to scalar ratio r which depend on the first and second derivatives of the inflaton potential. The information can be used to reconstruct the inflaton potential in the polynomial form up to some orders. However, for some classes of potentials, n s and r behave as n s (N ) and r(N ) universally in terms of the number of e-folds N . The universal behaviour of n s (N ) can be used to reconstruct a class of inflaton potentials. By parametrizing one of the parameters n s (N ), ǫ(N ) and φ(N ), and fitting the parameters in the models to the observational data, we obtain the constraints on the parameters and reconstruct the classes of the inflationary models which include the chaotic inflation, T-model, hilltop inflation, s-dual inflation, natural inflation and R 2 inflation.
By incorporating the curvature Ω k as a free parameter, it has been found that the tension between the high redshift cosmic microwave background (CMB) shift parameter R(z * ) data and the low redshift Type Ia supernova (SNIa) and baryonic acoustic oscillation (BAO) data from the combination of Sloan Digital Sky Surver (SDSS) and Two-Degree Field Galaxy Redshift Survey (2dFGRS) can be ameliorated, and both SNIa+BAO and SNIa+BAO+CMB favor that the decelerating parameter q(z) shows a rapid variation in the sign at the small redshift. In this paper, with the Monte Carlo Markov chain method, we re-examine the evolutionary behavior of q(z) using the latest observational data including the Union2 SNIa, BAO, and CMB data (R(z * ), l A (z * ), z * ) from Wilkinson Microwave Anisotropy Probe 7-yr (WMAP7). For the BAO data, four different data sets obtained from the Two-Degree Field Galaxy Survey, the combination of SDSS and 2dFGRS, the WiggleZ Dark Energy Survey and the Baryonic Oscillation Spectroscopic Survey, are used. Except for the spatially flat case constrained by SNIa+ the WiggleZ BAO data, both SNIa and other BAO+SNIa favor that the present cosmic acceleration is slowing down irrespective of whether the spatial curvature is included or not. However, once the WMAP7 CMB data is included, observations favor strongly the Lambda cold dark matter model, a spatially flat universe, and a speeding-up of the cosmic acceleration. Therefore, the inclusion of spatial curvature seems to has no effect on alleviating the tension between SNIa+BAO and CMB in clear contrast to the previous work in the literature.PACS numbers: 98.80.Cq
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.