The effect of anisotropic extra dimension in cosmology

Abstract

We consider five dimensional conformal gravity theory which describes an anisotropic extra dimension. Reducing the theory to four dimensions yields Brans-Dicke theory with a potential and a hidden parameter α which implements the anisotropy between the four dimensional spacetime and the extra dimension. We find that a range of value of the parameter α can address the current dark energy density compared to the Planck energy density. Constraining the parameter α and the other cosmological model parameters using the recent observational data consisting of the Hubble parameters, type Ia supernovae, and baryon acoustic oscillations, together with the Planck or WMAP 9-year data of the cosmic microwave background radiation, we find α > −2.05 for Planck data and α > −2.09 for WMAP 9-year data at 95% confidence level. We also obtained constraints on the rate of change of the effective Newtonian constant (G eff ) at present and the variation of G eff since the epoch of recombination to be consistent with observation. arXiv:1709.08499v2 [astro-ph.CO]

One‐parametric description for scalar field dark matter potentials

“…(17) By determining the proportionality constant , it is possible to calculate the evidence  directly from the MCMC chains. The software developed for this approach is called MCEVIDENCE, and it has been used to calculate the evidence for several alternative cosmological models, as it is shown by Archidiacono, Hannestad, & Lesgourgues (2020); Binnie & Pritchard (2019); Gómez-Valent, Pettorino, & Amendola (2020); Heavens, Fantaye, Sellentin, et al (2017); Kouwn, Oh, & Park (2018). Figure 3 shows the Bayes factor comparing all the SFDM models against the standard CDM.…”

“…By determining the proportionality constant a , it is possible to calculate the evidence ℰ directly from the MCMC chains. The software developed for this approach is called MCEvidence, and it has been used to calculate the evidence for several alternative cosmological models, as it is shown by Archidiacono et al (2020), Binnie & Pritchard (2019), Gómez‐Valent et al (2020), Heavens et al (2017b), and Kouwn et al (2018).…”

A Vanishingly Small Vector Mass from Anisotropy of Higher Dimensional Spacetime

“…In this work, we are interested in Minkowski vacuum solution, and we did not include the potential term in the action in Eq. (8). The isotropic case with β 1 = λ = z = 1 and β 2 = 0 leads to five-dimensional Weyl gravity with a zero potential for the field φ [7,8].…”

“…(8). The isotropic case with β 1 = λ = z = 1 and β 2 = 0 leads to five-dimensional Weyl gravity with a zero potential for the field φ [7,8]. In the anisotropic case, the action in Eq.…”

“…Conformal invariance can be incorporated with an extra (Weyl) scalar field and a real parameter z which describes the degree of anisotropy of conformal transformations between the four-dimensional spacetime, and extra dimensional metrics. A cosmological test of z was given, yielding an allowed range of the parameter [8].…”