Journal Article

We do not live in the <i>R</i><sub>h</sub> = <i>ct</i> universe

Maciej Bilicki and Marina Seikel

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 425, issue 3, pages 1664-1668
Published in print September 2012 | ISSN: 0035-8711
Published online September 2012 | e-ISSN: 1365-2966 | DOI:
We do not live in the Rh = ct universe

More Like This

Show all results sharing this subject:

  • Astronomy and Astrophysics


Show Summary Details



We analyse the possibility that our Universe could be described by the model recently proposed by Melia & Shevchuk, where the Hubble scale Rh = c/H is at all times equal to the distance ct that light has travelled since the big bang. In such a model, the scale factor is proportional to cosmic time, and there is neither acceleration nor deceleration of the expansion. We first point out problems with the very foundations of the model and its consequences for the evolution of the Universe. Next, we compare predictions of the model with observational data. As probes of the expansion we use distance data of Type Ia supernovae as well as Hubble rate data obtained from cosmic chronometers and radial baryon acoustic oscillations. We analyse the redshift evolution of the Hubble parameter and its redshift derivatives, together with the so-called diagnostic and the deceleration parameter. To reliably estimate smooth functions and their derivatives from discrete data, we use the recently developed Gaussian Processes in python (gapp) package. Our general conclusion is that the discussed model is strongly disfavoured by observations, especially at low redshifts (). In particular, it predicts specific constant values for the deceleration parameter and for redshift derivatives of the Hubble parameter, which is ruled out by the data.

Keywords: methods: data analysis; cosmology: observations; cosmology: theory

Journal Article.  3707 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.