Next Article in Journal
World-Line Formalism: Non-Perturbative Applications
Next Article in Special Issue
Tests of Lorentz Symmetry in the Gravitational Sector
Previous Article in Journal / Special Issue
A Solution of the Mitra Paradox
Article Menu
Issue 4 (December) cover image

Export Article

Open AccessArticle
Universe 2016, 2(4), 27;

Strategies to Ascertain the Sign of the Spatial Curvature

Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, Rio Grande do Norte, Brazil
Departamento de Física, Universidad Autónoma de Barcelona, Bellaterra, Barcelona 08193, Spain
Author to whom correspondence should be addressed.
Academic Editors: Lorenzo Iorio and Elias C. Vagenas
Received: 14 October 2016 / Revised: 14 November 2016 / Accepted: 15 November 2016 / Published: 24 November 2016
View Full-Text   |   Download PDF [450 KB, uploaded 24 November 2016]   |  


The second law of thermodynamics, in the presence of gravity, is known to hold at small scales, as in the case of black holes and self-gravitating radiation spheres. Using the Friedmann–Lemaître–Robertson–Walker metric and the history of the Hubble factor, we argue that this law also holds at cosmological scales. Based on this, we study the connection between the deceleration parameter and the spatial curvature of the metric, Ω k , and set limits on the latter, valid for any homogeneous and isotropic cosmological model. Likewise, we devise strategies to determine the sign of the spatial curvature index k. Finally, assuming the lambda cold dark matter model is correct, we find that the acceleration of the cosmic expansion is increasing today. View Full-Text
Keywords: mathematical cosmology; spatial curvatur; thermodynamics mathematical cosmology; spatial curvatur; thermodynamics

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Ferreira, P.C.; Pavón, D. Strategies to Ascertain the Sign of the Spatial Curvature. Universe 2016, 2, 27.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Universe EISSN 2218-1997 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top